Name: 新ウランボンド - 動画の周期律表 (New Uranium Bond - Periodic Table of Videos)
Uploaded: 2021-01-14T10:17:13.000Z
Duration: 8 min 53 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

welcome to the real world of doing uranium chemistry.

You have to put lots of gloves on to protect yourself.

関係詞節（制限と非制限）

Okay, so Dave has some of this nitride compound in this little vial which we've kept stored in the fridge freezer in the box just to make sure it's okay.

And it's all under the atmosphere of nitrogen dry nitrogen in this box to stop it going off because it reacts with water on oxygen, which is in the air that you and I breathe all the time.

This is, ah, paper we've just published on.

So this is ah, uranium nitride, which we've made on if you're wondering what on earth one of those is.

It's a compound with three bonds between uranium and nitrogen.

This is quite an important compound because it's taken literally decades to make one, and it was really quite tricky, but we got there in the end.

So this has been published in an American journal called Science, which is published every week.

And it's a pretty good general to get published.

Well, we started with this Iranian molecule just over here that this is a bit of a boring structure to show you.

So I thought I'd actually show you what it really looks like.

I hope you can tell immediately when you look at this is this is a really massive molecule.

You almost cannot see the uranium, which is in this molecule.

And it's this green sphere here that represents the uranium atom.

It's sat right in the middle of this structure and there's lots of shrubbery around the outside which is protecting that uranium center.

And this was really important for making this nitride molecule because the important thing about the way these groups wrapping around the uranium is when you look from the top, you can sort of see there's a pocket just coming in here, and that means we can introduce the group, but basically stop it doing any reactions with anything else in the vicinity.

What we did is we took this very simple molecule, So this basically is just a little ball and stick model off what we'd call sodium a site.

So three nitrogen atoms, all in a row, and what's interesting about this molecule is if you eject two electrons into it, you break one off the bonds.

I could just demonstrate that by pop it's gone on this fragment here.

That bond then comes round and you've got your triple bond in nitrogen is that's end to which is a gas, which is about 70% of the atmosphere.

What that leaves behind is a nitrogen autumn on a sodium on.

This now carries a charge, so it's very reactive, so it wants to bind to something.

And some of you may be thinking, well, where did the electrons come from in the first place while they came from the uranium in the middle of this structure, which means now it's positively charged, and this is negatively charged, so they're going to stick together.

So this night's June and you can see this isjust fiddly to do will jump in that now.

It's sort of a peer somewhere, but the key point is, this is a very reactive night, June, but it's got this sodium here to help stabilize.

If you think when you make it, so it kind of takes the sting out of the situation.

Quite a lot on means that you can isolate this molecule.

But what we really want to do then was pull that sodium away because then we'd get this night's June with a terminal linkage to the uranium.

And that's the thing that everybody had been changed her chasing for decades.

That is with a molecule called Crown Ether.

So it's just like a big circle going all the way around.

And there's four oxygen atoms he has shown in red, and this is what we called 12 crown for ether on before represents the fact that there's four oxygen's in this molecule on.

When you kind of put it on its side like this, you can kind of see how it looks a bit like a crown, this little sodium atom here that's not really to scale for this crown here, So I've just mocked up a quick sodium Catalonian, which is sort of comparable to the scale of the crown.

But one of these crowns isn't enough on its own So we have to bring in a second crown to the equation on.

When you have two of these, you can see how, with one crown on the bottom, on a sodium cattle and stuck in the middle on another crown on the top, you end up with the sodium completely trapped by these two crown ether molecules, so that removes it completely away from the uranium.

Those crowns came in almost like a claw and grabbed away.

Yeah, they just do a smash and grab and grab the sodium away on.

Just keep it nice and happy because it's got lots of oxygen atoms bonded to it.

So what you're left with now is our really massive compound with that nitrogen atoms bonded to uranium.

And the key point is because the nitrogen isn't bonded to anything else, and we know that nitrogen usually likes to make three bonds to other elements.

All those three bonds are to the uranium.

So just those two atoms in that structure there the really important bit.

But you need all of this other shrubbery to stabilize it because it's so reactive.

Okay, So this is one of the labs west of my group.

He's the guy that actually made this uranium.

Now he's gonna show you actually it in the glove box.

It's a real kind of dark red color, which is actually quite sensible because the uranium in this night tried.

It's what we would call an oxidation state.

Five on remaining compounds with the oxidation state tend to be very darkly, intensely colored, often read.

So that's the massive Ligon with uranium and nitrogen in the middle on the sodium with 2 12 ground for ethers as discreet pairs in a crystal.

Lattice has been a good three years trying to make this on a lot of hard work.

So I don't have to go through the process of making again.

What you told me is in the palace because we've analyzed it with a huge variety of techniques.

Each one on its own would not be convincing.

But when you bring them all together, it's absolutely incontrovertible.

That formulation is correct so that compounds being analyzed by enema infrared spectrometry we've burned it to get elemental percentages that are there in the molecule.

We've looked at what's called Elektronik absorption spectroscopy.

We've looked at the magnetic moment of the complex on we've also, I said, it reacts with water when you add water, that nitrogen, which is the night try, turns into ammonia and we've captured that ammonia measured.

How much of it we get to prove that that nitrogen really is a nitrogen.

Aisa topically labels it so nice gin would normally have a massive 14.

We've also incorporated the massive 15 isotope of nitrogen in there to prove with various of the techniques that probe the difference between the two isotopes that it really is a nitrogen.

So also, we're doing calculations to model, structured, understand where the electrons are.

When you put all those techniques together, you really do get a very good picture of what it is so Yeah, that's so here's a question for you.

How much do you reckon that powers work and money?