WEBVTT

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lost in the fog of a cosmic storm floating on

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whimsical wavelengths is the norm dancing through

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the stars chasing spectrums of light The countdown

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to the end of season two has begun. After this,

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there'll be three more brand new episodes. You

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don't want to miss them. They're going to be

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awesome. I'm not sure what order they're going

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to come out yet. I might end up actually making

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the one I thought was going to be the last one

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be the next one after this. I'm not entirely

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sure. Juggling different things. During the rest

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of the summer, there will be encores to fill

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the gap and keep the podcast feed fresh for those

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algorithms. It's also a chance to explore older

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episodes if you haven't gone back in time into

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the back catalog. There will also be more time

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to reminisce on the season that was later. Today,

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we're going to look at chemistry and material

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science. Maybe another terrible, nerdy science

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pickup line? I usually keep my 4F electrons buried

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behind two layers of shielding, but you've got

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the perfect sight symmetry to get through my

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guard. Now, to make that make sense, hopefully,

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anyway, Today we're going to be discussing lanthanide

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elements and how we can design molecules to build

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the technology for today and the future. In the

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periodic table there are 15 lanthanide elements

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ranging from atomic numbers 57 to 71. In my own

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field of mineral exploration I would call them

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rare earth elements. Perhaps you have heard about

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them on the news over the last few years. They

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are the linchpin of much of our modern technology.

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This group is special because of their properties.

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If you think back to grade school, we talked

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about elements and their valence shells. Electrons

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exist in regions away from the nucleus of the

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atom. All elements or atoms want to have full

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valence shells. Gases typically want to gain

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electrons. Lithium and all the rest of the alkalis

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have only one extra electron. They're so reactive

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in part because the energy released by losing

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that one electron. Lanthanide elements want to

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lose three electrons and become three plus. So

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far, no difference except the charge. But the

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bonding is very different. Most of our everyday

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substances, like water or carbon dioxide, they

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conveyantly bond, meaning they share electrons.

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The bonds themselves have shapes. Think of water

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again. The two hydrogen atoms form bonds at 104

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.5 degrees based on balancing electromagnetic

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forces on the atom. Lanthanides don't share.

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They exist. Once they are ionized, they will

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surround themselves with as many other atoms

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that have negative charge as they can. This makes

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them useful and opens up different possibilities

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to create novel molecules and structures. I think

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this is as far as I can credibly take this. So

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let's bring in today's guest. Today we have someone

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who describes his research interest on LinkedIn

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as looking at controlling the super molecule

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assembly of inorganic building blocks to yield

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materials with interesting properties. Kind of

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like building things out of tiny Lego bricks.

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He is a PhD candidate at Simon Fraser University

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in the Department of Chemistry in the Lesnoff

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Group. Please welcome Thomas Karpiak to the pod.

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Hi, thanks for having me. I'm excited to be here.

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And to be honest, I'm really happy that you came

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on. And before we get you to help explain the

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terrible pickup line that I used in the intro,

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a little bit about you. So how did you end up

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in a PhD project? Did it start with Legos as

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a kid and just kind of, you know, let's do this

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at the atomic scale? Yeah, I mean, I definitely

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did like Legos as a kid, although I think exclusively

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Star Wars Legos, so I don't know how that factored

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in. But I think I'm mainly drawn to chemistry

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because it's kind of like solving puzzles. Like

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even when you're introduced to it in high school,

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it's balancing equations, doing these sort of

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things. And thankfully, that thread even continues

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to like the highest levels of chemistry where

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even now. You know, it's a lot of just using

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extremely sophisticated instruments to really

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just understand how molecules behave, and otherwise

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you can't really, you know, it's a new area that

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no one's ever looked at before, so you have to

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sort of solve that puzzle. So I've been studying

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as a grad student at SFU for four years, and

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so I was first exposed to scientific research

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in my last year in my undergrad degree, where

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I did some summer research with... the Lesnov

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lab. So we really do think in terms of Lego bricks

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in our lab, our research is kind of like, instead

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of some chemistry people think of, which is doing

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synthetic work to stitch atoms together into

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a new molecule. Instead, we think of taking individual

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molecules and how are they going to assemble

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together to give a certain structure. that this

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material formed out of molecules will have properties

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beyond even what the molecules normally have.

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It sort of emerges from the structure. And so

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this is what we call supramolecular chemistry.

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And then my specific focus is on looking at lanthanides

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and their supramolecular chemistry. Okay, one

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follow -up question, because I'm sure I've walked

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through the area for the Lesnov group, but is

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there like... Any Lego statues of any sort of

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like a mascot or anything like that for the lab?

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I don't know if anybody's actually picked up

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or grabbed any Legos to make anything, but we

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probably should. It's a pretty good analogy for

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the sort of work we do. I'll have to think what

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we can do. Maybe we can make some molecules out

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of Legos. I'll have to crack open some old bins

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of toys. All right. So to the science, I guess

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to begin with, let's start with your topic, which

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is what are the lanthanides? Yeah, right. So

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the lanthanides, it's a series of 15 elements.

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It's tucked away at the bottom of the periodic

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table. It's lanthanum through to lutetium. And

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they differ from a lot of other elements that

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people are... used to in that their electrons

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are sitting in a different set of orbitals called

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the f orbitals so this is different than what

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organic chemists might play with stuff like carbon

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nitrogen oxygen these have their electrons in

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p orbitals maybe a bit simpler and then you know

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an inorganic chemist might work with transition

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metals something like zinc iron platinum these

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have their electrons in d orbitals and they have

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slightly more complicated behavior So the higher

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or the further along the alphabet you go, it's

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just further from the nucleus, right? Yeah, essentially.

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And generally, I guess you could say the chemistry

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gets a little bit more complicated or a little

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bit more obscure. And because of that reason,

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actually, comparatively, the lanthanides have

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been fairly understudied. So, for example, I

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have a quote here from... an introductory textbook

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to chemistry from 1971, and it states about the

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lanthanides, quote, lanthanum has only one important

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oxidation state in aqueous solution, the 3 -plus

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state. With few exceptions, this tells the whole

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boring story about the other 14 lanthanides,

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which is a little bit of... egg on their face

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because uh nowadays in the present day the lanthanides

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or or sometimes we refer them as the rare earth

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elements they're actually extremely industrially

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relevant um i pulled up some stats so so uh although

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In 1994, that's the last I could go back to.

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The global mining production of rare earth elements

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was 65 ,000 metric tons. That's quadrupled to

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the current day. And now the rare earth element

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market is valid at about $4 billion and is expected

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to raise to about $6 billion by 2030. So these

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elements are actually now really important for

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a lot of industries. The main one that people

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might have heard of is they're used in permanent

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magnets, which are now becoming really important

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because they're essential to electric vehicles,

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wind turbines. And then even so, like very small

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amounts of these elements are still found in

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almost all the technology you have, you know,

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like your cell phone, your TVs, your computers,

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your cars. And usually based on their magnetic

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properties and based on their luminescent properties,

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they're present in like... All of your LEDs,

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your lasers, they're used medicinally for bioimaging

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of cells. Even a funny one is that europium,

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which will emit red light when you use UV light

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to shine on it, it's actually used inside of

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the uro for anti -counterfeiting. I don't know

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if it was a coincidence that they used europium

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for the uro, but there's a lot of different uses

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for these elements. I think that just goes to

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show like they're always in the news, too, right?

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Like if we dive just sort of really adjacently

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into politics, I mean, geopolitically, Canada

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is being a place where we have a lot of them,

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but we don't mind them. And there's other places

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in the world like China, which has a stranglehold

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on them as far as like. the ability to export

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and use them, right? Yeah, you're 100 % correct.

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There's definitely a lot of interest and a lot

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of it stems politically about acquiring these

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metals. So you could say, even without getting

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into the details of the research yet, like this

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really is already, you know, it's something that

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could have a real effect on how we interact with

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the chemistry moving forward, without even getting

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into the research yet in the paper, right? Yeah,

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I mean, any steps forward with fundamental understanding

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of these elements can sort of trickle down to

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all of that. And the nice thing for me is that

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then I get to do the fundamental chemistry, which

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I enjoy, and the sort of puzzle solving there.

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And hopefully it can have some sort of ramifications

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in some of these places. Right. So to kind of,

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I think if there's one more step here, and I

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was honestly a little confused when... trying

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to brush up on my atomic chemistry for the understanding

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of this episode. Lanthanides have, well, you've

00:11:15.090 --> 00:11:16.929
already mentioned it, they become positively

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charged when they lose their outer electrons.

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And their outer electrons are not in, they're

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in orbits beyond F, is that correct? Or they're

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closer than F? This was the part that I was a

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little confused by because it's, you know, it's

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what also makes the pickup line joke work at

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the beginning, right? Yeah, so depending on which

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lanthanide you have, so they each will lose three

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electrons to become three plus charge, and all

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the remaining electrons will be residing in the

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F orbitals. The three that get lost, they can

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originate, well, two of them will originate from,

00:11:55.980 --> 00:11:59.299
it would be called the 6s2 orbitals. So those

00:11:59.299 --> 00:12:01.779
are like basically some orbitals that are beyond

00:12:01.779 --> 00:12:04.960
the F orbitals. But because the electrons in

00:12:04.960 --> 00:12:07.840
them, disappear in every case for all the lanthanides.

00:12:08.299 --> 00:12:10.419
You don't really have to worry about them. They're

00:12:10.419 --> 00:12:13.820
gone. You'd have to get to elements beyond the

00:12:13.820 --> 00:12:16.600
lanthanides, like if I remember my periodic table

00:12:16.600 --> 00:12:19.460
correctly, like up to lead. And then lead has

00:12:19.460 --> 00:12:22.440
particular chemistry because the electrons in

00:12:22.440 --> 00:12:25.639
the 6s2 orbital are then present and they're

00:12:25.639 --> 00:12:28.879
imparting certain chemistry. But the neat thing

00:12:28.879 --> 00:12:30.700
is that because they all lose three electrons

00:12:30.700 --> 00:12:33.240
and the only ones remaining are in the F orbital,

00:12:33.379 --> 00:12:36.620
they all have fairly similar chemistry from that

00:12:36.620 --> 00:12:40.960
perspective. Right. And I guess the next thing

00:12:40.960 --> 00:12:44.759
on my list is to figure out the difference between

00:12:44.759 --> 00:12:49.679
bonding with a lanthanide and what people were

00:12:49.679 --> 00:12:52.399
probably taught in high school of like, let's

00:12:52.399 --> 00:12:54.740
just take a water molecule, for instance, and

00:12:54.740 --> 00:12:58.620
you have that covalent bond. So what's the difference

00:12:58.620 --> 00:13:04.649
there? Yeah, so covalent bonding is where your

00:13:04.649 --> 00:13:08.370
atoms are sharing their electrons and forming

00:13:08.370 --> 00:13:11.710
bonds that have a very set geometry based on

00:13:11.710 --> 00:13:16.029
the electrons, which reside in orbitals that

00:13:16.029 --> 00:13:20.210
are spatially defined. So when you are overlapping

00:13:20.210 --> 00:13:22.769
those orbitals to share your electrons, you have

00:13:22.769 --> 00:13:26.190
a very set geometry of what forms. So every carbon

00:13:26.190 --> 00:13:29.299
is... you know gonna have either like a tetrahedral

00:13:29.299 --> 00:13:32.659
shape and it's gonna lead to structures we all

00:13:32.659 --> 00:13:35.820
know, like a diamond, or if they have a trigonal

00:13:35.820 --> 00:13:38.700
planar shape, they lead to graphite. So it's

00:13:38.700 --> 00:13:42.759
very well understood. To actually jump to understanding

00:13:42.759 --> 00:13:46.000
lanthanide bonding, it's actually good to segue

00:13:46.000 --> 00:13:49.600
through sort of the typical bonding in what we

00:13:49.600 --> 00:13:51.759
call transition metals, which are the block of

00:13:51.759 --> 00:13:53.879
metals in the middle of the periodic table, sort

00:13:53.879 --> 00:13:56.019
of what we think of as metals, like iron, zinc,

00:13:56.159 --> 00:13:58.620
stuff like that. Their bonding is sort of a middle

00:13:58.620 --> 00:14:01.769
ground because now... The electrons forming the

00:14:01.769 --> 00:14:04.490
bonds are in the d -orbitals. And d -orbitals

00:14:04.490 --> 00:14:06.970
are similar but more complicated. They stick

00:14:06.970 --> 00:14:09.610
out into different areas around the metal. They

00:14:09.610 --> 00:14:12.809
stick out from the nucleus. And like a lanthanide,

00:14:12.809 --> 00:14:16.730
the d - sorry, the transition metals are positively

00:14:16.730 --> 00:14:19.269
charged. We have to call them cations. So they

00:14:19.269 --> 00:14:22.769
form bonds with discrete anions that are going

00:14:22.769 --> 00:14:24.809
to sort of approach around. So there's some sort

00:14:24.809 --> 00:14:27.669
of like, you can imagine at the start, there's

00:14:27.669 --> 00:14:30.950
some sort of coulomic attraction that's part

00:14:30.950 --> 00:14:33.429
of that. Positive is attracted to negative, right?

00:14:33.509 --> 00:14:36.370
Back to physics like that. So just two charges

00:14:36.370 --> 00:14:40.029
is what you're saying? Yeah. Yeah, there's positive

00:14:40.029 --> 00:14:42.830
attracted to negative, but then also it becomes

00:14:42.830 --> 00:14:47.409
more nuanced because the electrons in the d -orbitals

00:14:47.409 --> 00:14:51.450
actually have a repulsion to the electrons on

00:14:51.450 --> 00:14:54.990
the anions. So you're overall attractive, but

00:14:54.990 --> 00:14:58.889
you have certain geometry that will be better

00:14:58.889 --> 00:15:02.289
to favor or to reduce repulsion between the orbitals

00:15:02.289 --> 00:15:05.870
and the anions. So this leads to various... like

00:15:05.870 --> 00:15:09.210
discrete geometries to reduce repulsion between

00:15:09.210 --> 00:15:12.730
orbitals so for example a transition metal the

00:15:12.730 --> 00:15:15.990
most common sort of picture you'll see is that

00:15:15.990 --> 00:15:19.610
central positively charged metal and then surrounded

00:15:19.610 --> 00:15:23.649
by six anions we call them ligands which the

00:15:23.649 --> 00:15:26.090
six of them will be sort of situated like when

00:15:26.090 --> 00:15:28.409
you have like a playing jack we call like an

00:15:28.409 --> 00:15:31.580
octahedron So you can imagine they're all six

00:15:31.580 --> 00:15:34.120
sticking out and sort of equally spaced around

00:15:34.120 --> 00:15:38.539
that central metal. But in comparison to this

00:15:38.539 --> 00:15:41.620
with the transition metal, when you get to a

00:15:41.620 --> 00:15:46.179
lanthanide, you see far different behavior because

00:15:46.179 --> 00:15:49.620
whereas a transition metal has its orbitals sticking

00:15:49.620 --> 00:15:52.679
out and wanting to interact with those ligands,

00:15:52.799 --> 00:15:56.960
the F orbitals are sucked in and buried. much

00:15:56.960 --> 00:16:00.120
closer to the nucleus. So there's minimal interaction

00:16:00.120 --> 00:16:03.960
with the environment. And this has to do with

00:16:03.960 --> 00:16:06.860
the particular F orbitals. Like say if you take

00:16:06.860 --> 00:16:09.440
like palladium, for example, in the transition

00:16:09.440 --> 00:16:13.360
metals, palladium has 46 electrons, right? But

00:16:13.360 --> 00:16:15.299
it's only 10 of those electrons we care about

00:16:15.299 --> 00:16:17.320
that are in those sort of frontier d orbitals

00:16:17.320 --> 00:16:20.000
and interacting with the ligands. The other 36

00:16:20.000 --> 00:16:23.379
are... the core electrons they're closer to the

00:16:23.379 --> 00:16:25.659
nucleus they're more tightly bound and they're

00:16:25.659 --> 00:16:27.679
already not really doing anything they're just

00:16:27.679 --> 00:16:30.659
the electrons you carry because you have all

00:16:30.659 --> 00:16:32.700
of your protons and neutrons you know as you

00:16:32.700 --> 00:16:35.320
go down the periodic table with a lanthanide

00:16:35.320 --> 00:16:38.909
though the whole situation flips the f orbitals

00:16:38.909 --> 00:16:42.590
actually lie closer to the nucleus and so all

00:16:42.590 --> 00:16:45.470
the orbitals that hold the core electrons are

00:16:45.470 --> 00:16:47.429
the ones that are farther out at the frontier

00:16:47.429 --> 00:16:49.649
so if you're a ligand and you're approaching

00:16:49.649 --> 00:16:53.250
this metal you're not actually seeing any orbitals

00:16:53.250 --> 00:16:55.730
to interact with you're just seeing sort of like

00:16:55.730 --> 00:16:58.950
you know it's like a core electron orbitals they

00:16:58.950 --> 00:17:01.389
don't really do anything so i kind of think of

00:17:01.389 --> 00:17:04.829
a lanthanide like like a big bowling ball of

00:17:04.829 --> 00:17:10.009
positive charge. And so all of the anionic ligands

00:17:10.009 --> 00:17:13.049
just want to sort of approach. And if you think

00:17:13.049 --> 00:17:16.990
back to elementary chemistry, the bonds we're

00:17:16.990 --> 00:17:19.450
going to form here are things like ionic bonds,

00:17:19.710 --> 00:17:23.750
just like how sodium. And in sodium chloride,

00:17:24.170 --> 00:17:26.789
you don't really have any electrons there guiding

00:17:26.789 --> 00:17:30.690
the bonds. You just have positive, big ball of

00:17:30.690 --> 00:17:32.690
positive, attracted to big ball of negative.

00:17:33.069 --> 00:17:35.869
So it's the same sort of situation with the lanthanide.

00:17:36.069 --> 00:17:38.750
So you can think of them a bit like you used

00:17:38.750 --> 00:17:40.509
a bowling ball. I'd use like a point source.

00:17:40.829 --> 00:17:44.650
It's just a positive charge that is going to

00:17:44.650 --> 00:17:46.549
interact with other negative charges. It's not

00:17:46.549 --> 00:17:50.619
doing anything. You're not changing the lanthanide

00:17:50.619 --> 00:17:52.539
in any way. You're not interacting with it in

00:17:52.539 --> 00:17:55.640
any way other than it's a charge. Yeah, well,

00:17:55.779 --> 00:17:59.079
it's kind of like the electrons on a transition

00:17:59.079 --> 00:18:03.700
metal have some sort of, they are driving a certain

00:18:03.700 --> 00:18:07.220
geometry to form around that metal, but the electrons

00:18:07.220 --> 00:18:09.319
in a lanthanide don't care that much. They're

00:18:09.319 --> 00:18:11.920
not having an influence on the chemistry. They're

00:18:11.920 --> 00:18:14.819
sort of tucked away inside. The reason that all

00:18:14.819 --> 00:18:17.240
this is really important, though, is that, you

00:18:17.240 --> 00:18:20.880
know, Well, the buried electrons don't care about

00:18:20.880 --> 00:18:23.819
what geometry forms around them. The geometry

00:18:23.819 --> 00:18:26.839
that forms actually ultimately decides how those

00:18:26.839 --> 00:18:31.279
electrons end up behaving. So the analogy I came

00:18:31.279 --> 00:18:34.539
up with is that it's kind of like how if you're

00:18:34.539 --> 00:18:37.750
a musician in a room. based on the shape of that

00:18:37.750 --> 00:18:39.970
room, the acoustics are going to change and you're

00:18:39.970 --> 00:18:42.329
going to feel that change. So it's just like

00:18:42.329 --> 00:18:44.269
these electrons sitting in a certain environment.

00:18:44.769 --> 00:18:47.130
As it changes, the behavior of the electrons

00:18:47.130 --> 00:18:49.789
is going to change. Us as chemists, we specifically

00:18:49.789 --> 00:18:53.190
like to contextualize this using concepts of

00:18:53.190 --> 00:18:55.730
symmetry. So like, for example, if you're this

00:18:55.730 --> 00:18:59.210
musician, if you're in a, you could be in like

00:18:59.210 --> 00:19:01.490
a triangular shaped room, a square shaped room,

00:19:01.589 --> 00:19:05.170
a pentagonal shaped room. We would say that all

00:19:05.170 --> 00:19:07.289
of those rooms have a sort of rotational symmetry.

00:19:07.609 --> 00:19:10.009
If you close your eyes and you take the triangle

00:19:10.009 --> 00:19:13.470
and rotate the room by 120 degrees and open your

00:19:13.470 --> 00:19:16.500
eyes, it still looks the same to you. So there's

00:19:16.500 --> 00:19:19.859
symmetry inside that room. There's other types

00:19:19.859 --> 00:19:22.400
of symmetry. You could imagine a concert hall,

00:19:22.599 --> 00:19:25.559
right? If you're standing at the stage of a concert

00:19:25.559 --> 00:19:27.720
hall, then there's no rotational symmetry there,

00:19:27.839 --> 00:19:30.599
but the left side of the room looks like a mirror

00:19:30.599 --> 00:19:33.220
image of the right side of the room, right? So

00:19:33.220 --> 00:19:34.740
that's a different type of symmetry. This is

00:19:34.740 --> 00:19:37.900
mirror symmetry. And we use that language as

00:19:37.900 --> 00:19:39.819
chemists a lot of the time to understand what's

00:19:39.819 --> 00:19:43.240
happening. Because again, based on the symmetry

00:19:43.240 --> 00:19:46.059
of the environment this lanthanide is put on,

00:19:46.180 --> 00:19:48.319
then those electrons are going to behave differently.

00:19:48.339 --> 00:19:51.299
And that's what informs the properties that they

00:19:51.299 --> 00:19:56.119
end up having. Okay, so when I say, I usually

00:19:56.119 --> 00:19:59.400
keep my 4F electrons buried behind two layers

00:19:59.400 --> 00:20:02.079
of shielding, you've got the perfect site symmetry

00:20:02.079 --> 00:20:06.130
to get through my guard. I guess that works because

00:20:06.130 --> 00:20:10.230
you need symmetry to be able to interact at all

00:20:10.230 --> 00:20:14.789
or to be connected to the 4F electrons. And under

00:20:14.789 --> 00:20:17.950
normal circumstances, they are not going to impart

00:20:17.950 --> 00:20:21.069
anything to the room. Yeah, exactly. And it's

00:20:21.069 --> 00:20:24.809
a very flipped situation than any other element

00:20:24.809 --> 00:20:29.630
where there's a really, you know, there's an

00:20:29.630 --> 00:20:34.019
interplay between electrons. want a certain environment

00:20:34.019 --> 00:20:37.099
and that environment changes how the electrons

00:20:37.099 --> 00:20:42.299
behave but here the we have to use our chemistry

00:20:42.299 --> 00:20:45.180
to force a certain environment to control how

00:20:45.180 --> 00:20:47.829
the electrons behave and you know To reiterate,

00:20:48.029 --> 00:20:50.970
the behavior of electrons is what causes all

00:20:50.970 --> 00:20:54.390
properties in chemistry. So this is what's going

00:20:54.390 --> 00:20:57.210
to cause these elements to show their unique

00:20:57.210 --> 00:21:01.069
magnetic properties and unique luminescent properties

00:21:01.069 --> 00:21:03.369
and allow us to have these fancy applications

00:21:03.369 --> 00:21:06.650
for LEDs and magnets and stuff like that. You

00:21:06.650 --> 00:21:09.289
know, what you just said there was something

00:21:09.289 --> 00:21:12.009
that obviously rings true in my head, but I don't

00:21:12.009 --> 00:21:13.809
think I've ever heard anyone say it that way,

00:21:13.849 --> 00:21:16.319
at least not. in a very, very long time, that

00:21:16.319 --> 00:21:18.960
the chemistry that we interact with on a daily

00:21:18.960 --> 00:21:21.740
basis is really controlled by the electrons.

00:21:22.019 --> 00:21:24.259
So I guess that should be a take -home for anyone

00:21:24.259 --> 00:21:25.839
who's listening along. But more importantly,

00:21:25.960 --> 00:21:28.279
also, do you know anyone that would use such

00:21:28.279 --> 00:21:30.440
a terrible pickup line at a chemistry concert?

00:21:32.059 --> 00:21:34.619
I'm not sure what your success rate would be.

00:21:35.539 --> 00:21:37.660
They'd have to definitely know their lanthanide

00:21:37.660 --> 00:21:38.480
chemistry. I think success is getting a laugh

00:21:38.480 --> 00:21:41.880
and not actually picking anybody up. Or getting

00:21:41.880 --> 00:21:43.980
that confused look is like, you're for cereal?

00:21:45.700 --> 00:21:51.779
Yeah. All right. So to take this to from now,

00:21:51.880 --> 00:21:53.859
we've understood that the electrons are what

00:21:53.859 --> 00:21:56.359
make the chemistry and the interaction and the

00:21:56.359 --> 00:21:58.220
properties of the chemistry that we interact

00:21:58.220 --> 00:22:01.799
with. So I know this might be a tall ask. How

00:22:01.799 --> 00:22:07.519
do we go from this group of... Lanthanides, this

00:22:07.519 --> 00:22:10.539
group, has a wide variety of different properties

00:22:10.539 --> 00:22:13.420
that we care about, from luminescence to magnetics

00:22:13.420 --> 00:22:17.900
to superconductance. So how do those electrons

00:22:17.900 --> 00:22:22.640
create these properties? Yeah, so there is 15

00:22:22.640 --> 00:22:25.779
of these lanthanides, and each one has different

00:22:25.779 --> 00:22:29.420
numbers of electrons. and then as you're putting

00:22:29.420 --> 00:22:31.619
different numbers of electrons inside these orbitals

00:22:31.619 --> 00:22:34.839
they're interacting differently the electrons

00:22:34.839 --> 00:22:37.500
repel each other so we call it an electronic

00:22:37.500 --> 00:22:41.619
structure which says that you know how happy

00:22:41.619 --> 00:22:44.799
is this element as we arrange these electrons

00:22:44.799 --> 00:22:47.619
in different ways um you know this has to do

00:22:47.619 --> 00:22:49.279
with these orbitals which are sort of like a

00:22:49.279 --> 00:22:52.440
you know not really a physical they don't really

00:22:52.440 --> 00:22:54.619
physically exist but we sort of have to understand

00:22:54.619 --> 00:22:57.849
them to the basis of like you know quantum mechanics

00:22:57.849 --> 00:23:00.170
and stuff like this but ultimately it's just

00:23:00.170 --> 00:23:02.829
how are these electrons moving around happily

00:23:02.829 --> 00:23:05.569
inside that element so for example for luminescence

00:23:05.569 --> 00:23:09.049
we can have light which is a form of energy be

00:23:09.049 --> 00:23:12.089
absorbed by a lanthanide element this energy

00:23:12.089 --> 00:23:15.009
needs to go somewhere so what happens is that

00:23:15.009 --> 00:23:17.269
your electrons which are in a happy configuration

00:23:17.269 --> 00:23:20.049
will then take on extra energy and this lets

00:23:20.049 --> 00:23:22.170
them go into maybe some different configuration

00:23:22.170 --> 00:23:26.119
that's more destabilized. Eventually these electrons

00:23:26.119 --> 00:23:28.099
are going to want to relax back down to their

00:23:28.099 --> 00:23:31.079
normal configuration and along the way they'll

00:23:31.079 --> 00:23:34.819
lose some energy in the form of like vibrations

00:23:34.819 --> 00:23:38.119
out of the molecule but eventually we need to

00:23:38.119 --> 00:23:41.720
go from one configuration back to the the original

00:23:41.720 --> 00:23:44.380
one and that's going to mean losing the rest

00:23:44.380 --> 00:23:45.960
of our energy we've picked up from the light

00:23:45.960 --> 00:23:48.859
and you know in order to conserve energy that

00:23:48.859 --> 00:23:53.319
means the element then has to emits all the extra

00:23:53.319 --> 00:23:57.339
energy in the form of another photon so we basically

00:23:57.339 --> 00:24:01.579
absorb one photon it could be something like

00:24:01.579 --> 00:24:04.220
ultraviolet light which has a lot of energy and

00:24:04.220 --> 00:24:06.839
then after we lose a bit internally in some processes

00:24:06.839 --> 00:24:10.400
of the the lanthanide then we eventually emit

00:24:10.400 --> 00:24:13.420
another photon but it's going to be lower in

00:24:13.420 --> 00:24:16.900
energy and if you think back to electromagnetism

00:24:16.900 --> 00:24:20.720
in the spectrum of light, if we take less energy

00:24:20.720 --> 00:24:23.299
from ultraviolet, we actually end up in the visible

00:24:23.299 --> 00:24:27.759
spectrum. So this means that, for example, I

00:24:27.759 --> 00:24:30.579
think I mentioned it, europium, if it accepts

00:24:30.579 --> 00:24:34.880
UV photons, it will ultimately end up emitting

00:24:34.880 --> 00:24:41.299
a very characteristic red light. Terbium is another

00:24:41.299 --> 00:24:45.160
lanthanide. It will emit green light. And even

00:24:45.160 --> 00:24:47.519
then, you know, beyond what we're familiar with

00:24:47.519 --> 00:24:49.380
with the visible spectrum, you can have some

00:24:49.380 --> 00:24:52.480
lanthanides like neodymium, erbium, ytterbium,

00:24:52.559 --> 00:24:55.900
they actually emit in what we call the near IR,

00:24:56.160 --> 00:24:59.579
so the infrared, near infrared light. And those

00:24:59.579 --> 00:25:02.460
wavelengths are actually very important, for

00:25:02.460 --> 00:25:06.680
example, for like... Surgeries and medicinal

00:25:06.680 --> 00:25:11.319
applications, fiber optic and telecommunications,

00:25:11.359 --> 00:25:14.460
both of those technologies hinge on the near

00:25:14.460 --> 00:25:18.660
IR emission of neodymium in lasers and erbium

00:25:18.660 --> 00:25:22.640
in fiber optic cables. And yeah, so every property

00:25:22.640 --> 00:25:25.359
of these lanthanides sort of hinges on these

00:25:25.359 --> 00:25:27.220
same sort of ideas. They have their magnetic

00:25:27.220 --> 00:25:30.079
properties because they have so many unpaired

00:25:30.079 --> 00:25:32.640
electrons that can behave in certain ways to

00:25:32.640 --> 00:25:35.549
create magnetic moments. The superconducting

00:25:35.549 --> 00:25:38.150
properties might be a bit beyond my pay grade,

00:25:38.269 --> 00:25:41.309
but for sure, as far as I know, a lot of the

00:25:41.309 --> 00:25:45.549
cutting -edge research there is finding some

00:25:45.549 --> 00:25:48.529
success using lanthanides. For example, there's

00:25:48.529 --> 00:25:52.309
some very funny compounds where their chemical

00:25:52.309 --> 00:25:58.099
formula is lanthanum H10, I believe. Which, if

00:25:58.099 --> 00:26:00.079
you're a chemist, is a very strange formula,

00:26:00.140 --> 00:26:03.259
because normally you don't have 10 hydrogen atoms

00:26:03.259 --> 00:26:07.200
alongside one other lanthanide. But again, like

00:26:07.200 --> 00:26:11.140
I said, a bit beyond my pay grade. It just means

00:26:11.140 --> 00:26:14.980
future work, right? Yeah, of course. Okay, well,

00:26:15.059 --> 00:26:17.740
the paper at the center of the episode is Strategies

00:26:17.740 --> 00:26:20.779
to Control the Geometry and Symmetry around Lanthanide

00:26:20.779 --> 00:26:23.519
Centers for Tailored Luminescence and Magnetism.

00:26:24.009 --> 00:26:27.470
Now that we know what lanthanides are, we know

00:26:27.470 --> 00:26:29.230
a little bit about their properties, we can talk

00:26:29.230 --> 00:26:31.309
about the paper more directly. We've kind of

00:26:31.309 --> 00:26:33.450
already talked about symmetry, so let's, I guess,

00:26:33.529 --> 00:26:36.789
start there with geometry. What does it really

00:26:36.789 --> 00:26:39.009
mean? Like, that's the center of the paper, is

00:26:39.009 --> 00:26:42.470
it not? Yeah, for sure. Yeah, we can definitely

00:26:42.470 --> 00:26:46.789
dive into that. So in this paper, we did... Where

00:26:46.789 --> 00:26:49.069
I sort of haven't mentioned one thing, it kind

00:26:49.069 --> 00:26:52.730
of ties back to my bowling ball analogy. I consider

00:26:52.730 --> 00:26:55.069
them like bowling balls because the other aspect

00:26:55.069 --> 00:26:57.390
of these metals, you know, because they're all

00:26:57.390 --> 00:26:59.210
the way at the bottom of the periodic table,

00:26:59.369 --> 00:27:03.200
they also have a really large size. They're large,

00:27:03.359 --> 00:27:07.059
they're big elements, they're big cations. So

00:27:07.059 --> 00:27:09.680
whereas I mentioned a transition metal might

00:27:09.680 --> 00:27:12.700
have six ligands around it, lanthanides can have,

00:27:12.960 --> 00:27:15.759
you know, it could have six, but it could have

00:27:15.759 --> 00:27:19.680
eight, nine, up to 12 different atoms or ligands

00:27:19.680 --> 00:27:22.019
approaching around it. And this is another thing

00:27:22.019 --> 00:27:25.319
that... complicates trying to control their geometry.

00:27:25.599 --> 00:27:29.619
So in this specific project in this paper, we

00:27:29.619 --> 00:27:33.380
did limit ourselves to an analysis of lanthanides

00:27:33.380 --> 00:27:36.140
with eight ligands, which are the most common.

00:27:36.440 --> 00:27:39.940
And so if you imagine taking a central point,

00:27:40.059 --> 00:27:42.700
which is the lanthanide, and all the different

00:27:42.700 --> 00:27:45.279
ways you could arrange eight other points around

00:27:45.279 --> 00:27:49.430
that to give a sort of, you know, equal distance

00:27:49.430 --> 00:27:52.230
between them all. It actually turns out there's

00:27:52.230 --> 00:27:55.750
about five ways you can reasonably do this. One

00:27:55.750 --> 00:27:58.970
of them is probably pretty obvious to people.

00:27:59.130 --> 00:28:02.049
You can take your eight ligands and arrange it

00:28:02.049 --> 00:28:05.970
as a cube around that lanthanide. So a lanthanide

00:28:05.970 --> 00:28:08.890
could have eight of its ligands basically arranged

00:28:08.890 --> 00:28:13.049
as a cube around it. As chemists, we would call

00:28:13.049 --> 00:28:15.819
this actually a very high symmetry environment,

00:28:16.359 --> 00:28:18.740
right? Because if you take a cube, you can keep

00:28:18.740 --> 00:28:20.799
rotating it around and it always looks the same.

00:28:21.279 --> 00:28:24.019
But actually a cubic arrangement is not actually

00:28:24.019 --> 00:28:27.259
very common. It's not very favorable to, you

00:28:27.259 --> 00:28:28.680
know, what we're trying to do is we're trying

00:28:28.680 --> 00:28:31.759
to minimize repulsion between these ligands.

00:28:32.299 --> 00:28:34.279
That's what's controlling the geometry because

00:28:34.279 --> 00:28:37.440
each ligand is negatively charged. They repel

00:28:37.440 --> 00:28:41.230
each other. And so if you take a cube, you can

00:28:41.230 --> 00:28:45.410
actually do a better job of maximizing the distance

00:28:45.410 --> 00:28:47.670
between each ligand by just taking the top face

00:28:47.670 --> 00:28:52.910
and twisting it by 45 degrees. Then we get what's

00:28:52.910 --> 00:28:56.049
called a square antiprism. And so this is the

00:28:56.049 --> 00:28:59.210
most common geometry you encounter with a coordinate,

00:28:59.509 --> 00:29:01.970
with lanthanides with eight ligands. And the

00:29:01.970 --> 00:29:05.259
symmetry of this, we still consider this. a fairly

00:29:05.259 --> 00:29:08.039
high symmetry you can now take that shape and

00:29:08.039 --> 00:29:11.059
if you look down its axis you can rotate it by

00:29:11.059 --> 00:29:14.000
90 degrees and it will then look the same as

00:29:14.000 --> 00:29:17.299
it did so we say that this has four -fold rotational

00:29:17.299 --> 00:29:20.859
symmetry you can rotate it by sequential four

00:29:20.859 --> 00:29:23.940
-fold rotations or 90 degree rotations four times

00:29:23.940 --> 00:29:26.759
to return back to where you were But we have

00:29:26.759 --> 00:29:29.359
five total geometries we can have. Another one

00:29:29.359 --> 00:29:32.960
that's the next most common is called dodecahedral.

00:29:33.099 --> 00:29:35.420
It's a little bit harder to visualize. You can

00:29:35.420 --> 00:29:39.420
imagine taking your hands as like C -shapes and

00:29:39.420 --> 00:29:41.819
sort of cupping them like this. And then if you

00:29:41.819 --> 00:29:44.579
sort of, you're encapsulating that middle space

00:29:44.579 --> 00:29:47.099
with your cupped hands. If you arrange sort of

00:29:47.099 --> 00:29:50.000
eight atoms around your two hands, this would

00:29:50.000 --> 00:29:52.819
give you dodecahedral geometry. And this is sort

00:29:52.819 --> 00:29:55.349
of a bit lower symmetry. Another one that's a

00:29:55.349 --> 00:29:58.549
bit easier to visualize than that is hexagonal

00:29:58.549 --> 00:30:02.089
bipyramidal. This is simply putting six of your

00:30:02.089 --> 00:30:06.289
atoms as a hexagon, as sort of the equator around

00:30:06.289 --> 00:30:09.890
your lanthanide, and then putting one and the

00:30:09.890 --> 00:30:12.130
second one at the top and bottom to make this

00:30:12.130 --> 00:30:16.529
sort of hexagonal bipyramid is where the name

00:30:16.529 --> 00:30:19.170
comes from. This you would also consider to be

00:30:19.170 --> 00:30:22.170
fairly high symmetry. We have sort of this six

00:30:22.170 --> 00:30:26.869
-fold rotational symmetry. And lastly is bicapped

00:30:26.869 --> 00:30:29.309
trigonal prismatic geometry. This is actually

00:30:29.309 --> 00:30:32.250
the third most common geometry. It's a bit also

00:30:32.250 --> 00:30:34.970
hard to visualize. I guess I would recommend

00:30:34.970 --> 00:30:37.910
anyone to look up. The photos in the paper will

00:30:37.910 --> 00:30:39.630
do a lot better job than me trying to explain

00:30:39.630 --> 00:30:42.130
them. But this is kind of like taking six of

00:30:42.130 --> 00:30:45.769
your atoms as triangles above and below the lanthanide,

00:30:45.809 --> 00:30:48.309
and then the remaining two sort of go outward

00:30:48.309 --> 00:30:51.730
in the equatorial plane to give this. It's the

00:30:51.730 --> 00:30:55.809
lowest symmetry possible range. But what we were

00:30:55.809 --> 00:30:58.569
interested to do in this paper is, you know,

00:30:58.569 --> 00:31:03.029
take these five geometries. And what was interesting

00:31:03.029 --> 00:31:05.660
to us is that Each of these geometries, we could

00:31:05.660 --> 00:31:07.400
look through the literature and see that they

00:31:07.400 --> 00:31:12.140
all have unique use cases where they're pivotal

00:31:12.140 --> 00:31:14.819
to allowing certain properties or behaviors to

00:31:14.819 --> 00:31:18.299
occur. We have examples in the literature. But

00:31:18.299 --> 00:31:24.519
do people have the strategies to use our chemical

00:31:24.519 --> 00:31:26.940
tools, our molecules that we want to put around

00:31:26.940 --> 00:31:30.039
the lanthanide to specifically cause a certain

00:31:30.039 --> 00:31:33.450
geometry to occur? And that was the goal of this

00:31:33.450 --> 00:31:37.329
paper. If I understood that sentence correctly,

00:31:37.549 --> 00:31:42.470
the goal of the paper was to predict, based on

00:31:42.470 --> 00:31:46.210
an ion, what symmetry or what shape it was going

00:31:46.210 --> 00:31:49.869
to take. Well, we wanted to use existing tools

00:31:49.869 --> 00:31:53.730
that can take a molecular structure and tell

00:31:53.730 --> 00:31:58.940
us what the geometry is. What we had came up

00:31:58.940 --> 00:32:02.559
with is that if we can look at all the existing

00:32:02.559 --> 00:32:06.420
data that exists to date of lanthanide molecules,

00:32:06.680 --> 00:32:09.700
and the way we can do this is essentially as

00:32:09.700 --> 00:32:12.779
chemists, we look at molecular structures by

00:32:12.779 --> 00:32:16.079
determining their structures with x -rays and

00:32:16.079 --> 00:32:18.859
determining crystal structures. And so there's

00:32:18.859 --> 00:32:22.980
a database that to date has like, I think, 1

00:32:22.980 --> 00:32:27.829
.5 million structures of different... So if we

00:32:27.829 --> 00:32:30.410
could pull out every single one that has a lanthanide

00:32:30.410 --> 00:32:35.029
and run these structures through some programs

00:32:35.029 --> 00:32:38.509
that tell us what the geometry is and then also

00:32:38.509 --> 00:32:41.569
tie it back to see what the exact structures

00:32:41.569 --> 00:32:45.750
are, then we can know which sort of molecules

00:32:45.750 --> 00:32:49.509
we can use to specifically get a certain geometry.

00:32:49.930 --> 00:32:54.059
So you're taking... molecules that you potentially

00:32:54.059 --> 00:32:56.839
have never, that are not in the literature, that

00:32:56.839 --> 00:32:59.619
are not part of this, and suggesting what geometry

00:32:59.619 --> 00:33:03.619
they would probably take. I think, yeah, ideally

00:33:03.619 --> 00:33:06.079
that's what it would allow, is that we sort of

00:33:06.079 --> 00:33:11.160
wanted to sort of distill the existing information,

00:33:11.200 --> 00:33:13.319
the data that's out there, so we could sort of

00:33:13.319 --> 00:33:16.619
have general guidelines, so that someone could

00:33:16.619 --> 00:33:19.859
take new molecules they're looking at that they're

00:33:19.859 --> 00:33:23.000
thinking of sort of wrapping around a lanthanide,

00:33:23.039 --> 00:33:26.099
and they would have a better idea of what geometry

00:33:26.099 --> 00:33:29.319
it might give, or what modification do I need

00:33:29.319 --> 00:33:34.019
to make to my molecules to have a certain geometry

00:33:34.019 --> 00:33:36.740
to maximize for this property I'm trying to target.

00:33:37.019 --> 00:33:41.940
So to sort of be able to distill that information

00:33:41.940 --> 00:33:45.380
to have some general guidelines. So you could

00:33:45.380 --> 00:33:48.559
say, that this is almost like a seminal piece

00:33:48.559 --> 00:33:51.279
of work. Like this is what's going to allow for

00:33:51.279 --> 00:33:55.220
speedier discoveries of like the different properties

00:33:55.220 --> 00:33:58.940
of different anions and being able to really

00:33:58.940 --> 00:34:02.259
use those chemistries in ways that as of yet

00:34:02.259 --> 00:34:04.279
are undiscovered, but this gives them the tool

00:34:04.279 --> 00:34:06.720
to try to narrow down where they want to go.

00:34:07.220 --> 00:34:10.400
Yeah, I mean, I hope that people will find it,

00:34:10.440 --> 00:34:13.159
you know, useful. I mean, it's not that a lot

00:34:13.159 --> 00:34:16.369
of these sort of concepts didn't already exist.

00:34:16.550 --> 00:34:18.489
Of course, chemists have been trying to tune

00:34:18.489 --> 00:34:20.809
their molecules to gain certain properties for

00:34:20.809 --> 00:34:24.250
a long time. But we hoped that even just through

00:34:24.250 --> 00:34:27.090
doing this work and putting it out there, maybe

00:34:27.090 --> 00:34:29.869
it gives people sort of a different perspective

00:34:29.869 --> 00:34:33.489
to think about it slightly differently. And,

00:34:33.489 --> 00:34:36.489
you know, if we can see in one area of the literature

00:34:36.489 --> 00:34:38.769
that people are using one certain strategy to

00:34:38.769 --> 00:34:42.429
do something and Somebody else is doing something

00:34:42.429 --> 00:34:44.610
else or they're missing something over in another

00:34:44.610 --> 00:34:46.909
area. There's a lot of lanthanide chemistry going

00:34:46.909 --> 00:34:50.309
on, but maybe to pull it all out of the data

00:34:50.309 --> 00:34:53.349
autonomously and then have it to present to people,

00:34:53.409 --> 00:34:56.210
maybe people can sort of see more holistically

00:34:56.210 --> 00:34:58.010
what are the different strategies people can

00:34:58.010 --> 00:35:02.210
use. Okay, so I guess that's a good thing to

00:35:02.210 --> 00:35:05.530
segue into. So what did people use in the distant

00:35:05.530 --> 00:35:09.030
past? I have this, let's put some stuff beside

00:35:09.030 --> 00:35:12.769
it and guess and check. They weren't able to

00:35:12.769 --> 00:35:15.929
predict what a particular symmetry was going

00:35:15.929 --> 00:35:18.750
to be, so they had to go figure it out through

00:35:18.750 --> 00:35:21.889
x -rays. Or was there a bit more of a predictive

00:35:21.889 --> 00:35:26.030
tool? When did we make that switch? Yeah, I guess

00:35:26.030 --> 00:35:30.989
historically, again, so for... As an example

00:35:30.989 --> 00:35:33.369
of what this sort of chemistry would look like

00:35:33.369 --> 00:35:36.409
in practice, when we talk about ligands and putting

00:35:36.409 --> 00:35:41.110
atoms around lanthanides, what we really mean

00:35:41.110 --> 00:35:44.909
is not just the atoms that make those eight points,

00:35:44.949 --> 00:35:46.849
but those atoms are ultimately attached to something

00:35:46.849 --> 00:35:50.030
on the outside. So, for example, you can take...

00:35:50.320 --> 00:35:54.500
Or you could even imagine like a claw machine

00:35:54.500 --> 00:35:58.360
game that goes and picks up a ball out of one

00:35:58.360 --> 00:36:00.739
of those machines, right? That claw that comes

00:36:00.739 --> 00:36:03.800
down and grabs it, you know, some people do chemistry

00:36:03.800 --> 00:36:06.519
where they're trying to replicate that claw shape

00:36:06.519 --> 00:36:09.800
with a molecule. So it grabs onto a lanthanide.

00:36:09.900 --> 00:36:13.980
We call these chelates in general. Chelate, I

00:36:13.980 --> 00:36:16.280
think, I could be wrong. I think it is Greek

00:36:16.280 --> 00:36:23.170
for claw. Claw machine, claw is like three pronged,

00:36:23.170 --> 00:36:25.489
I think. But you could imagine trying to make

00:36:25.489 --> 00:36:28.869
molecules that are two pronged. That's very common.

00:36:28.969 --> 00:36:32.309
Three pronged. You could have a molecule that's

00:36:32.309 --> 00:36:34.989
four pronged. And so if you think about a eight

00:36:34.989 --> 00:36:37.369
coordinate lanthanide, maybe you take two of

00:36:37.369 --> 00:36:39.550
those four pronged molecules and you go from

00:36:39.550 --> 00:36:42.769
top and bottom and encapsulate them. And so then,

00:36:42.849 --> 00:36:45.980
you know, with these different... sort of classes

00:36:45.980 --> 00:36:48.079
of molecules. There's ones that people have done

00:36:48.079 --> 00:36:50.260
a lot of work because they found that they would

00:36:50.260 --> 00:36:52.579
give a certain geometry and then they can go

00:36:52.579 --> 00:36:55.420
deeper into that same system and see how to further

00:36:55.420 --> 00:36:58.320
tune it. And it is essentially like sort of you

00:36:58.320 --> 00:37:02.219
design a ligand, you attach it to your lanthanide,

00:37:02.239 --> 00:37:04.219
and then it is sort of, well, now I have to go

00:37:04.219 --> 00:37:06.300
get the crystal structure and see what happened.

00:37:06.659 --> 00:37:09.380
So there is sort of that guess and check, unless

00:37:09.380 --> 00:37:11.400
you're sort of working with an existing system

00:37:11.400 --> 00:37:15.289
where you have some... predisposition that you

00:37:15.289 --> 00:37:19.050
suspect already. So I think there's a missing

00:37:19.050 --> 00:37:21.389
side of this, because at least up to this point,

00:37:21.409 --> 00:37:23.429
and this only just occurred to me, I'm really

00:37:23.429 --> 00:37:25.570
thinking about these on the molecule scale. And

00:37:25.570 --> 00:37:28.909
then you just mentioned crystals again. So you

00:37:28.909 --> 00:37:31.389
have to be dealing with more than just a single

00:37:31.389 --> 00:37:33.190
molecule here if you're going to create a crystal

00:37:33.190 --> 00:37:36.449
lattice and be able to look at this. So what

00:37:36.449 --> 00:37:39.820
is that like in the lab? Like, do you have to

00:37:39.820 --> 00:37:41.840
have it at a certain temperature? How do you

00:37:41.840 --> 00:37:47.780
maintain purity? How do you do that? To grow

00:37:47.780 --> 00:37:50.980
like a crystal of what you need to study? Yeah,

00:37:51.059 --> 00:37:53.920
yeah. So, I mean, crystal growth is a really,

00:37:53.940 --> 00:37:56.559
really interesting aspect because you kind of,

00:37:56.559 --> 00:37:58.139
you need to do it. You need to be able to grow

00:37:58.139 --> 00:38:00.780
a crystal of whatever. You could have a discrete

00:38:00.780 --> 00:38:02.880
molecule that contains a lanthanide that you

00:38:02.880 --> 00:38:06.010
need to study. You could have... You know, something

00:38:06.010 --> 00:38:08.010
like what I would study, which is a super molecular

00:38:08.010 --> 00:38:11.789
system that's assembling and contains lanthanides.

00:38:11.829 --> 00:38:14.690
You could have a material like a mineral that

00:38:14.690 --> 00:38:16.630
contains a lanthanide. But in every case, you

00:38:16.630 --> 00:38:20.469
need to use X -ray diffraction of a crystal to

00:38:20.469 --> 00:38:23.050
see its structure. And so, yeah, it really is

00:38:23.050 --> 00:38:26.030
challenging to grow crystals. But sometimes there's

00:38:26.030 --> 00:38:28.190
nothing more than what, you know, you can buy

00:38:28.190 --> 00:38:30.309
like a kit from Walmart if you're a kid to do

00:38:30.309 --> 00:38:33.250
crystal growth. I mean, you take like... copper

00:38:33.250 --> 00:38:36.590
sulfate or you take sugar or salt and you leave

00:38:36.590 --> 00:38:40.469
it in solution and as it slowly sits there and

00:38:40.469 --> 00:38:43.010
the solution is evaporating it's becoming more

00:38:43.010 --> 00:38:46.969
concentrated the the molecules eventually are

00:38:46.969 --> 00:38:49.170
unhappy that it's too concentrated. It needs

00:38:49.170 --> 00:38:52.269
to turn into a solid. So the trick is that if

00:38:52.269 --> 00:38:54.809
that's slow enough, then the molecules kind of

00:38:54.809 --> 00:38:57.449
have time to find their place. And instead of

00:38:57.449 --> 00:39:00.170
sort of making some sort of powdery sort of substance,

00:39:00.409 --> 00:39:03.150
they'll actually grow into an ordered crystal.

00:39:03.570 --> 00:39:06.090
You don't need big crystals for X -ray diffraction.

00:39:06.210 --> 00:39:08.230
I mean, we're not growing, you know, centimeter

00:39:08.230 --> 00:39:10.030
-sized crystals. You can really use something

00:39:10.030 --> 00:39:13.380
as small as... Fractions of a centimeter, millimeter

00:39:13.380 --> 00:39:16.139
scale, but still they need to be nice quality

00:39:16.139 --> 00:39:19.039
crystals and it's definitely... I'm sorry, I'm

00:39:19.039 --> 00:39:20.860
going down all kinds of rabbit holes now. Are

00:39:20.860 --> 00:39:25.099
you using water as the solvent or something else,

00:39:25.159 --> 00:39:30.360
random? Yeah, I mean, as a chemist, I mean, obviously

00:39:30.360 --> 00:39:33.239
the chemicals are your tools, but beyond that

00:39:33.239 --> 00:39:37.960
also solvents are a massive aspect of how you

00:39:37.960 --> 00:39:40.880
control what happens because your solvent...

00:39:41.360 --> 00:39:43.920
Water is a solvent, but you could have things

00:39:43.920 --> 00:39:47.619
people are familiar with. Ethanol, as chemists,

00:39:47.639 --> 00:39:50.480
we still use that as a solvent. It has different

00:39:50.480 --> 00:39:53.619
properties of how molecules dissolve into it,

00:39:53.699 --> 00:39:56.539
how molecules bounce around inside that solvent.

00:39:56.840 --> 00:39:59.300
So a lot of times to make sure you can grow the

00:39:59.300 --> 00:40:01.820
right crystal, it's about choosing the right

00:40:01.820 --> 00:40:04.880
solvents or mixtures of solvents. A lot of obscure

00:40:04.880 --> 00:40:08.059
stuff, liquids that people have never heard of.

00:40:09.610 --> 00:40:13.809
A whole range. So a big aspect of it is choosing

00:40:13.809 --> 00:40:17.829
the right solvent. We've gone from electrons

00:40:17.829 --> 00:40:22.849
determining chemistry to bowling balls of positive

00:40:22.849 --> 00:40:27.369
charge to how we put together lanthanide molecules

00:40:27.369 --> 00:40:30.769
as little Lego blocks to growing crystals all

00:40:30.769 --> 00:40:35.630
in one episode. I guess, though, for this, the

00:40:35.630 --> 00:40:37.469
paper, though, everything really does come back

00:40:37.469 --> 00:40:40.780
to symmetry, right? Including, like, you'll see

00:40:40.780 --> 00:40:42.900
that symmetry directly in the crystal lattice

00:40:42.900 --> 00:40:45.340
and the way that that crystal is growing. And

00:40:45.340 --> 00:40:46.960
that's the whole point of hitting it with the

00:40:46.960 --> 00:40:49.460
x -rays. So you can see that lattice effect.

00:40:50.739 --> 00:40:53.340
Yeah, yeah. No, you're 100 % correct. I mean,

00:40:53.360 --> 00:40:56.340
the fact that x -rays diffract off of a crystal,

00:40:56.500 --> 00:41:01.460
the understanding of that is, I mean, steeped

00:41:01.460 --> 00:41:04.639
in symmetry and using symmetry to understand

00:41:04.639 --> 00:41:09.260
that for sure. Again, we do a lot of our... We

00:41:09.260 --> 00:41:12.119
use the language of symmetry to conceptualize

00:41:12.119 --> 00:41:16.679
a lot of stuff in this realm of chemistry. Have

00:41:16.679 --> 00:41:19.860
you ever, or I guess someone in the lab, because

00:41:19.860 --> 00:41:21.300
you're dealing with lots of other people, all

00:41:21.300 --> 00:41:22.860
of a sudden just something doesn't make much

00:41:22.860 --> 00:41:25.920
sense and they have to go and figure out was

00:41:25.920 --> 00:41:28.500
there contamination instead of like a change

00:41:28.500 --> 00:41:30.719
in symmetry? Because the x -ray doesn't give

00:41:30.719 --> 00:41:32.780
you chemistry itself. It's giving you the crystal

00:41:32.780 --> 00:41:38.750
lattice, right? Yeah, I think me. In my day -to

00:41:38.750 --> 00:41:42.250
-day lab, I think I've definitely had a vial

00:41:42.250 --> 00:41:44.269
where I was trying to make some certain molecule,

00:41:44.469 --> 00:41:47.889
saw a crystal in there, went down to our diffractometer

00:41:47.889 --> 00:41:50.949
and determined its structure, and it was just

00:41:50.949 --> 00:41:54.730
some other thing. It's very common for us to

00:41:54.730 --> 00:41:57.269
accidentally run. Okay, I won't say very common,

00:41:57.309 --> 00:41:59.949
but for example, I've definitely accidentally

00:41:59.949 --> 00:42:02.630
mounted a crystal and determined its structure

00:42:02.630 --> 00:42:05.489
and found out that it was actually just sodium

00:42:05.489 --> 00:42:08.800
chloride. I've done that before because, you

00:42:08.800 --> 00:42:11.320
know, salt's pretty pervasive. If you're combining

00:42:11.320 --> 00:42:16.840
ionic species, then they have counter ions. And

00:42:16.840 --> 00:42:19.179
if the counter ion crystallizes instead of what

00:42:19.179 --> 00:42:22.070
you're trying to make, then... And that can happen.

00:42:22.150 --> 00:42:25.550
So for sure, it happens. It can be disappointing.

00:42:25.670 --> 00:42:28.809
Or sometimes it can be surprising if you were

00:42:28.809 --> 00:42:30.929
trying to do one thing and instead some other

00:42:30.929 --> 00:42:32.789
molecule came out and crystallized. And then,

00:42:32.809 --> 00:42:35.210
you know, you have to spend six months trying

00:42:35.210 --> 00:42:38.030
to reproduce that result, which has happened

00:42:38.030 --> 00:42:40.349
to some people. That's kind of where I was going.

00:42:40.570 --> 00:42:43.030
I was like, hmm, I have a feeling this could

00:42:43.030 --> 00:42:46.070
derail a whole PhD for quite a while if something

00:42:46.070 --> 00:42:48.989
weird came out of it. Yeah, in our group, we

00:42:48.989 --> 00:42:52.159
have... We have one structure. So, I mean, it's

00:42:52.159 --> 00:42:55.000
a, you know, it's a computer file that people

00:42:55.000 --> 00:42:57.079
pass around, basically. I think it's existed

00:42:57.079 --> 00:43:01.139
for maybe 10 years where, you know, my boss with

00:43:01.139 --> 00:43:02.820
a new student will be like, hey, look at this

00:43:02.820 --> 00:43:06.199
structure. Isn't this cool? But he won't tell

00:43:06.199 --> 00:43:08.559
them that six people have already spent, you

00:43:08.559 --> 00:43:12.559
know, 10 years trying to remake it. Sort of a,

00:43:12.639 --> 00:43:15.820
what do you call that? Not a golden, I don't

00:43:15.820 --> 00:43:17.900
remember the name. But yeah, we've been trying

00:43:17.900 --> 00:43:19.690
to redo it for a long time. that's hilarious

00:43:19.690 --> 00:43:22.710
um okay let's let's circle back to something

00:43:22.710 --> 00:43:24.690
that i kind of skipped over because this is one

00:43:24.690 --> 00:43:27.710
of the reasons you mentioned luminescence and

00:43:27.710 --> 00:43:31.050
i think one of the reasons we this technology

00:43:31.050 --> 00:43:34.150
or this paper really allows for is trying to

00:43:34.150 --> 00:43:37.510
figure out what magnetization is going to work

00:43:37.510 --> 00:43:40.809
best and um the way i'm going to try to explain

00:43:40.809 --> 00:43:43.809
it and that you correct me and so we'll flip

00:43:43.809 --> 00:43:45.889
it on its head and see see how good i did as

00:43:45.889 --> 00:43:48.920
a prepping for this All materials, once it has

00:43:48.920 --> 00:43:53.699
charge, can eventually kind of flip its direction.

00:43:53.880 --> 00:43:57.820
They call it quantum tunneling or relax. So it

00:43:57.820 --> 00:44:01.059
changes its magnetization vector over time. And

00:44:01.059 --> 00:44:03.280
so part of the lanthanides being plus three,

00:44:03.360 --> 00:44:06.710
if you get the right symmetry. you hopefully

00:44:06.710 --> 00:44:09.849
are going to be able to create something that's

00:44:09.849 --> 00:44:12.389
long lasting. So therefore, you can use it in

00:44:12.389 --> 00:44:13.909
something like a hard drive. You can be able

00:44:13.909 --> 00:44:17.230
to keep information around longer. Did I get

00:44:17.230 --> 00:44:19.909
most of that correct? Yeah, no, you're on the

00:44:19.909 --> 00:44:21.969
right track. So what you're talking about there

00:44:21.969 --> 00:44:25.250
are what's called single molecule magnets or

00:44:25.250 --> 00:44:29.579
SMMs. This is like... This is a pretty highly

00:44:29.579 --> 00:44:33.460
active research area, at least in academics currently.

00:44:33.679 --> 00:44:37.139
These are molecules, like you said, that have

00:44:37.139 --> 00:44:41.900
a large magnetic moment that you can sort of

00:44:41.900 --> 00:44:44.559
manipulate, but the magnetic moment will only...

00:44:45.579 --> 00:44:48.239
sort of exist in a coherent state once you've

00:44:48.239 --> 00:44:51.780
cooled it to a low enough temperature. And like

00:44:51.780 --> 00:44:54.059
you said, it's sort of like this magnetic moment.

00:44:54.179 --> 00:44:57.360
You can imagine it pointing either up or down.

00:44:57.579 --> 00:45:01.039
And if you tie that back to like a one or a zero

00:45:01.039 --> 00:45:04.659
in a computer, then the theory is that, you know,

00:45:04.659 --> 00:45:07.280
if you could toggle to control switching between

00:45:07.280 --> 00:45:09.960
up and down, then you could have each molecule

00:45:09.960 --> 00:45:12.760
storing information. And, you know, then you're

00:45:12.760 --> 00:45:17.630
shrinking. data storage down to the atomic level,

00:45:17.809 --> 00:45:21.489
like maybe a 100 -fold increase in information

00:45:21.489 --> 00:45:24.230
density. So people are really interested in this

00:45:24.230 --> 00:45:28.090
area. But you're right. So actually, the quantum

00:45:28.090 --> 00:45:33.530
tunneling of magnetization is the remaining drawback

00:45:33.530 --> 00:45:37.789
in lanthanide SMMs that needs to be dealt with.

00:45:38.090 --> 00:45:41.369
The analogy I could come up with to explain this

00:45:41.369 --> 00:45:45.780
is An SMM is kind of like, you can imagine somebody,

00:45:45.980 --> 00:45:48.320
some person who only likes to sleep on their

00:45:48.320 --> 00:45:51.559
side, okay? So they are happy to be either facing

00:45:51.559 --> 00:45:55.760
left or facing right, right? But in order to

00:45:55.760 --> 00:45:58.380
swap between those two positions, they have to,

00:45:58.460 --> 00:46:01.639
for a moment, be sleeping facing upright, and

00:46:01.639 --> 00:46:04.039
they don't like that. That's unfavorable. So

00:46:04.039 --> 00:46:07.059
in chemistry, we call this... this is like an

00:46:07.059 --> 00:46:09.519
energy barrier in order to switch between the

00:46:09.519 --> 00:46:12.199
two configurations so like either pointing up

00:46:12.199 --> 00:46:15.039
or down it needs to pass through a configuration

00:46:15.039 --> 00:46:17.719
that's not happy and there's a barrier to that

00:46:17.719 --> 00:46:20.159
this is why once the temperature is high enough

00:46:21.559 --> 00:46:23.679
there's enough energy to easily pass over the

00:46:23.679 --> 00:46:26.619
barrier and you can't control it. So as people

00:46:26.619 --> 00:46:29.179
have been designing lanthanide SMMs, I mean,

00:46:29.219 --> 00:46:32.659
the main thing they can do is use ligands where

00:46:32.659 --> 00:46:35.980
their electron density is placed such to make

00:46:35.980 --> 00:46:39.980
that intermediate position really unhappy for

00:46:39.980 --> 00:46:42.480
the electrons in the lanthanide to switch from

00:46:42.480 --> 00:46:47.369
up to down. But quantum... tunneling of the magnetization

00:46:47.369 --> 00:46:49.889
it's it's as the name suggests it's a quantum

00:46:49.889 --> 00:46:52.449
mechanical phenomenon which is kind of like if

00:46:52.449 --> 00:46:55.909
you're watching this this guy sleep and you blink

00:46:55.909 --> 00:46:58.289
and all of a sudden he was facing left and now

00:46:58.289 --> 00:47:01.730
he's just facing right and you you totally missed

00:47:01.730 --> 00:47:03.630
it there was nothing you could do to control

00:47:03.630 --> 00:47:07.989
it i when we talk about tunneling it's a in quantum

00:47:07.989 --> 00:47:10.409
mechanics it means skipping right through an

00:47:10.409 --> 00:47:14.099
energy barrier And you can't even control it.

00:47:14.199 --> 00:47:17.380
So if you have quantum tunneling occurring with

00:47:17.380 --> 00:47:20.880
your molecule to a high degree, then your ups

00:47:20.880 --> 00:47:23.360
and downs are getting scrambled. And you can't

00:47:23.360 --> 00:47:25.239
get store information unless you continue to

00:47:25.239 --> 00:47:27.579
cool it lower and lower. And the goal right now

00:47:27.579 --> 00:47:30.960
is to design molecules that can operate at high

00:47:30.960 --> 00:47:33.320
enough temperatures where you don't have to...

00:47:34.110 --> 00:47:36.690
It's a similar problem with superconducting.

00:47:36.710 --> 00:47:39.050
If they only operate it at a very low temperature,

00:47:39.349 --> 00:47:43.429
you need to use things like helium for cooling,

00:47:43.590 --> 00:47:47.429
and that's a very expensive and dwindling resource.

00:47:48.190 --> 00:47:51.150
Yeah, and the neat thing that sort of drew us

00:47:51.150 --> 00:47:53.590
into this is that the quantum tunneling of magnetization,

00:47:53.730 --> 00:47:57.969
to fix this problem, it's purely a problem of

00:47:57.969 --> 00:48:01.250
symmetry. So what researchers have found is that

00:48:01.250 --> 00:48:04.329
in your molecule, if you can keep the magnetic

00:48:04.329 --> 00:48:08.090
moment aligned with a very high symmetry axis,

00:48:08.510 --> 00:48:12.369
so like in the square antiprism I mentioned or

00:48:12.369 --> 00:48:16.480
in a hexagonal bipyramidal, geometry, then as

00:48:16.480 --> 00:48:18.760
it's aligned with this very high symmetry, that

00:48:18.760 --> 00:48:21.239
sort of helps it know where it's supposed to

00:48:21.239 --> 00:48:24.119
face and keep it from slipping out of its orientation

00:48:24.119 --> 00:48:26.960
and then accidentally just like you blink and

00:48:26.960 --> 00:48:28.940
it switches to the other orientation. If you

00:48:28.940 --> 00:48:31.800
can have very high symmetry, it helps protect

00:48:31.800 --> 00:48:33.760
against that. And so that's sort of what people

00:48:33.760 --> 00:48:38.219
are looking into now. And that's why we thought

00:48:38.219 --> 00:48:41.550
it would be in that. Very useful to provide some

00:48:41.550 --> 00:48:44.610
tools to know how to better control symmetry.

00:48:44.989 --> 00:48:47.570
Right. See, everything does come back to symmetry

00:48:47.570 --> 00:48:50.489
with Lance and I. At least for me. I'm sure there's

00:48:50.489 --> 00:48:52.750
some other aspects, but for me, I find this very

00:48:52.750 --> 00:48:56.070
fascinating. So for sure, I'd like to hope that

00:48:56.070 --> 00:48:59.869
a lot of it is based on symmetry. So just kind

00:48:59.869 --> 00:49:03.030
of summing up before we get to a question where

00:49:03.030 --> 00:49:07.039
this is going for future work, the paper... broadly

00:49:07.039 --> 00:49:09.980
speaking, is a series of techniques that can

00:49:09.980 --> 00:49:15.619
help predict what shape or symmetry or geometry

00:49:15.619 --> 00:49:20.260
individual negatively charged molecules will

00:49:20.260 --> 00:49:23.019
make with a lanthanide. And so that way you can

00:49:23.019 --> 00:49:26.079
help predict its chemistry. That's a two sentence

00:49:26.079 --> 00:49:29.000
sum up. Is that roughly correct? Yeah, yeah,

00:49:29.000 --> 00:49:32.840
exactly. Yeah. Cool. So how is this going to

00:49:32.840 --> 00:49:35.739
be used for the future? Does this mean eventually

00:49:35.739 --> 00:49:40.179
this may lead to brighter screens, maybe finally

00:49:40.179 --> 00:49:43.400
get quantum computing off the shelf and into

00:49:43.400 --> 00:49:47.280
our rooms? Or where do you think this is going

00:49:47.280 --> 00:49:51.559
to lead us to? Yeah, I mean, I hope that the

00:49:51.559 --> 00:49:57.050
project exists as a useful tool for... sort of

00:49:57.050 --> 00:50:00.090
making it a bit easier for this one aspect. You

00:50:00.090 --> 00:50:01.909
know, for sure in all of these applications,

00:50:02.210 --> 00:50:05.449
the point is that there is a lot of other considerations

00:50:05.449 --> 00:50:08.489
when you're trying to make essentially the best

00:50:08.489 --> 00:50:11.750
example of something, right? I mean, you have

00:50:11.750 --> 00:50:13.769
so many other choices that you have to make or

00:50:13.769 --> 00:50:15.730
that you're constrained by. You know, if you're

00:50:15.730 --> 00:50:18.510
trying to make the best single molecule magnet,

00:50:18.789 --> 00:50:21.750
then you also have to deal with constraints on

00:50:21.750 --> 00:50:25.250
what do the ligands look like? How do their electrons

00:50:26.250 --> 00:50:29.769
force that magnetic moment to behave. Even now,

00:50:29.829 --> 00:50:31.829
sort of the cutting edge research is saying,

00:50:32.010 --> 00:50:35.949
well, once that molecule is inside of a crystal,

00:50:36.190 --> 00:50:39.829
how are you dealing with other things like vibrations?

00:50:40.510 --> 00:50:44.349
Vibrations can cause, can help you pass over

00:50:44.349 --> 00:50:46.250
that energy barrier as well, sort of like your

00:50:46.250 --> 00:50:48.449
molecule gets bumped and its spin gets switched,

00:50:48.610 --> 00:50:51.190
right? So how are we now going to design crystals

00:50:51.190 --> 00:50:53.840
that best? hold these molecules, or how are we

00:50:53.840 --> 00:50:56.000
going to figure out how to put these molecules

00:50:56.000 --> 00:50:59.179
anchored onto surfaces, like as a material science

00:50:59.179 --> 00:51:05.179
perspective. So I don't think that this project

00:51:05.179 --> 00:51:08.719
in and of itself is like a silver bullet, but

00:51:08.719 --> 00:51:12.420
obviously in any field as you move towards sort

00:51:12.420 --> 00:51:15.940
of the best example, you need to be accounting

00:51:15.940 --> 00:51:19.179
for so many things that it can help people better

00:51:19.179 --> 00:51:21.820
understand at least this one aspect. So yeah,

00:51:21.860 --> 00:51:25.599
maybe the future is quantum computing and this

00:51:25.599 --> 00:51:29.820
data storage idea I'm talking about. For luminescence,

00:51:29.820 --> 00:51:33.000
there's some really exciting stuff with, I mentioned,

00:51:33.019 --> 00:51:36.280
bioimaging and anti -counterfeiting as well.

00:51:36.880 --> 00:51:39.860
People are looking at, you can have the luminescence

00:51:39.860 --> 00:51:43.750
change. As a function of external stimuli, so

00:51:43.750 --> 00:51:47.289
you could have maybe toxic gas sensors, you could

00:51:47.289 --> 00:51:50.530
have fancy thermometers that use luminescence

00:51:50.530 --> 00:51:53.530
as their output. This is some of the things people

00:51:53.530 --> 00:51:57.030
are looking at. Actually, one thing that I think

00:51:57.030 --> 00:51:59.710
might be quite interesting that we were able

00:51:59.710 --> 00:52:04.150
to pull out from our results, which I really

00:52:04.150 --> 00:52:06.389
haven't touched to up to this point, but I mean,

00:52:06.409 --> 00:52:10.019
there's 15 of these lanthanides, right? One factor

00:52:10.019 --> 00:52:12.039
of them, which is why it hasn't really mattered

00:52:12.039 --> 00:52:14.360
up to this point, is that all 15 of them, although

00:52:14.360 --> 00:52:16.619
they have different physical properties, chemically

00:52:16.619 --> 00:52:18.840
they behave very similarly. That's why they're

00:52:18.840 --> 00:52:22.599
kind of treated as this monolith. But actually,

00:52:22.840 --> 00:52:24.440
you know, it's funny. The reason why they're

00:52:24.440 --> 00:52:27.519
called rare earths is not actually that they're

00:52:27.519 --> 00:52:30.900
rare. They're actually quite abundant. They're

00:52:30.900 --> 00:52:34.059
called rare because when you have an ore or a

00:52:34.059 --> 00:52:37.320
mineral and you need to get, like, I need just

00:52:37.320 --> 00:52:40.679
neodymium. out of this ore to sell it. Well,

00:52:40.699 --> 00:52:43.880
they're so chemically similar that it's extremely

00:52:43.880 --> 00:52:46.760
difficult to separate them. And in fact, the

00:52:46.760 --> 00:52:50.179
separation procedures are quite nasty environmentally.

00:52:50.760 --> 00:52:54.630
So with that... that perspective of mining and

00:52:54.630 --> 00:52:56.989
as they're becoming these critical minerals,

00:52:57.329 --> 00:52:59.989
a lot of people are actually interested in being

00:52:59.989 --> 00:53:03.289
able to selectively recycle certain lanthanides

00:53:03.289 --> 00:53:06.469
from magnet waste or electronic waste. So in

00:53:06.469 --> 00:53:08.929
our paper, we were actually able to say that

00:53:08.929 --> 00:53:12.909
the preference for a certain geometry actually

00:53:12.909 --> 00:53:15.789
slightly changes as you go across this series

00:53:15.789 --> 00:53:18.010
of lanthanides. So there's a little bit of a...

00:53:18.250 --> 00:53:20.650
There's a little bit of a trend of the chemical

00:53:20.650 --> 00:53:24.250
similarity is it actually does have a slight

00:53:24.250 --> 00:53:27.070
nuance to it for what geometry is preferred.

00:53:27.389 --> 00:53:29.889
So if you could use those slight difference in

00:53:29.889 --> 00:53:32.869
preferences for a certain geometry, maybe you

00:53:32.869 --> 00:53:36.050
could design a molecule that can selectively

00:53:36.050 --> 00:53:39.030
grab onto and extract a certain lanthanide, just

00:53:39.030 --> 00:53:41.809
like a claw machine, right? And if you can pull

00:53:41.809 --> 00:53:44.989
out... the lanthanides from a waste mixture and

00:53:44.989 --> 00:53:48.690
be able to selectively recycle it, then this

00:53:48.690 --> 00:53:50.869
is also something people are very, very interested

00:53:50.869 --> 00:53:55.070
in. Cool. Okay. Well, I've had you here for almost

00:53:55.070 --> 00:53:57.170
an hour. I do have one more question, actually.

00:53:57.250 --> 00:53:59.570
I was debating whether or not to ask it because

00:53:59.570 --> 00:54:02.989
you brought it up. Vibrations and crystals and

00:54:02.989 --> 00:54:06.150
symmetry, some of these symmetry geometries are

00:54:06.150 --> 00:54:11.389
not the same in all directions. And isotropic,

00:54:11.550 --> 00:54:13.250
they're not, you know, they're different in different

00:54:13.250 --> 00:54:17.150
directions. I assume that has a lot to do with

00:54:17.150 --> 00:54:20.489
the properties of that material as well. Yeah,

00:54:20.570 --> 00:54:24.110
for sure. So like a cube is perfectly isotropic.

00:54:24.409 --> 00:54:29.329
It's the same on all directions. Yeah, every

00:54:29.329 --> 00:54:34.690
other geometry will have some amount of... anisotropicness.

00:54:34.750 --> 00:54:37.210
It looks different along different directions.

00:54:37.449 --> 00:54:40.590
So that is directly what causes some of these

00:54:40.590 --> 00:54:43.369
properties. So when you think of like a single

00:54:43.369 --> 00:54:46.650
molecule magnet, by definition, actually, they

00:54:46.650 --> 00:54:50.969
need to have an anisotropic environment, because

00:54:50.969 --> 00:54:53.929
that anisotropic environment is what means that

00:54:53.929 --> 00:54:58.030
it's Easier for the magnetic moment. Yeah, exactly.

00:54:58.269 --> 00:55:00.550
And it's anisotropic where on one direction it's

00:55:00.550 --> 00:55:02.949
unfavored. That's why if you have a cubic geometry,

00:55:03.210 --> 00:55:05.050
you can't use that for a single molecule magnet

00:55:05.050 --> 00:55:07.909
because it's isotropic. So for sure, this is

00:55:07.909 --> 00:55:11.090
very important for all of these properties. I

00:55:11.090 --> 00:55:16.110
wish I had asked that earlier. Okay, so now to

00:55:16.110 --> 00:55:18.329
wrap it up, call outs. This is your chance to

00:55:18.329 --> 00:55:23.309
call out future work. A funny thing you guys

00:55:23.309 --> 00:55:25.699
have as a tradition in the lab. I don't know.

00:55:26.179 --> 00:55:29.480
Whatever tickles your fancy. Well, I guess I

00:55:29.480 --> 00:55:35.119
can shout out that. So this project itself, it

00:55:35.119 --> 00:55:38.559
was sort of like my primary research in the lab

00:55:38.559 --> 00:55:41.159
is more sort of hands -on, whereas this project

00:55:41.159 --> 00:55:45.099
was really only on a computer. It was writing

00:55:45.099 --> 00:55:48.639
code. It was analyzing data. But the fun thing

00:55:48.639 --> 00:55:51.400
is where we're going next with this is that I

00:55:51.400 --> 00:55:54.480
personally am kind of taking the ideas that And

00:55:54.480 --> 00:55:57.639
from a lot of reading and going through the literature,

00:55:57.699 --> 00:56:00.460
I kind of have now sort of gained maybe a bit

00:56:00.460 --> 00:56:02.539
better understanding and then my own results

00:56:02.539 --> 00:56:06.159
from this analysis. So the fun part now is going

00:56:06.159 --> 00:56:08.679
back into the lab and seeing if I can sort of

00:56:08.679 --> 00:56:12.780
prove myself right. Can I use my own ideas of

00:56:12.780 --> 00:56:18.400
guiding symmetry? And can I make some molecule

00:56:18.400 --> 00:56:23.369
that has improved? luminescence. Day to day in

00:56:23.369 --> 00:56:26.489
our lab we don't really do the magnetism stuff

00:56:26.489 --> 00:56:28.809
too much but we do look at the luminescence and

00:56:28.809 --> 00:56:32.769
so I am working on a project right now that we

00:56:32.769 --> 00:56:36.730
think we can directly tie in our case actually

00:56:36.730 --> 00:56:40.750
the super molecular structure inside of a crystal

00:56:40.750 --> 00:56:45.239
and how we're using that. to in turn control

00:56:45.239 --> 00:56:48.739
geometry, control symmetry, and cause improved

00:56:48.739 --> 00:56:51.559
luminescence. So this is something I'm really

00:56:51.559 --> 00:56:53.980
excited about and we're kind of looking into

00:56:53.980 --> 00:56:56.460
now. So that's where this is kind of going next.

00:56:57.039 --> 00:56:59.739
That's a perfect way of just describing science.

00:57:00.219 --> 00:57:02.940
It's not just one paper. It's always like, okay,

00:57:03.059 --> 00:57:05.320
what does that give me? How can I use this? How

00:57:05.320 --> 00:57:08.519
can I test it? And that's how it all moves on.

00:57:08.659 --> 00:57:12.340
You ready for the infamous last question? I think

00:57:12.340 --> 00:57:15.750
so. You think so? All right. Hit us with your

00:57:15.750 --> 00:57:20.789
favorite science joke. All right. I had to go

00:57:20.789 --> 00:57:22.809
with the chemistry joke. I mean, that seemed

00:57:22.809 --> 00:57:26.190
the correct thing to do. So here's my joke. Two

00:57:26.190 --> 00:57:28.690
atoms are walking down the street. One says to

00:57:28.690 --> 00:57:31.869
the other, I think I lost my electron. And the

00:57:31.869 --> 00:57:35.210
other says, are you sure? First one says, yeah,

00:57:35.250 --> 00:57:40.070
I'm positive. Very, very nice. Very nice. I think

00:57:40.070 --> 00:57:42.710
a lot of chemistry jokes are. Or not the ones

00:57:42.710 --> 00:57:44.710
that get a laugh, but get a little bit of a...

00:57:44.710 --> 00:57:47.230
A groan. I know, I know. But those are the best

00:57:47.230 --> 00:57:49.809
ones. Like, I'm a big fan of dad humor. Well,

00:57:49.869 --> 00:57:51.590
thank you very much for coming on to the show,

00:57:51.610 --> 00:57:54.429
sir. Thank you for having me. That brings another

00:57:54.429 --> 00:57:56.409
episode to a close. Remember, if you haven't

00:57:56.409 --> 00:58:00.289
done so already, leave a rating, a review for

00:58:00.289 --> 00:58:02.849
the show. It really helps the show get out to

00:58:02.849 --> 00:58:07.530
new people. And we've only got three more episodes

00:58:07.530 --> 00:58:12.219
left in season two. I'll see you in two weeks.

00:59:01.659 --> 00:59:04.460
Always seeking.