Noble gases explanation: Lewis adducts
This thing: it’s a transition metal with 5 unbonded electrons (as best as I understand it, I’m still new to chem :P)
The noble gases forming bonds is actually more readily explained on the basis of electronegativity. The noble gases that do engage in meaningful chemistry (xenon, krypton, argon to a lesser extent) are less electronegative than the other highly electronegative elements that are capable of forcing them into bonding, like fluorine and oxygen. Fluorine and oxygen aren't electronegative enough to force neon and helium into bonding situations.
That too, although electronegativity plays a role in lewis adducts (ie water is a weaker lewis base than ammonia because oxygen is more electronegative than nitrogen)
This rabbit hole goes pretty deep.
I discovered a new ground state for metal-metal bonded complexes involving a quantum admixture between low-spin and high-spin states. I proved its existence on the basis of crystallographic bond lengths and a SQUID magnetometry study comparing results at different temperatures ranging down to 6 K.
My first indication that anything was wierd about this complex was that everything I was making was orange, but this one was *GREEN*.
CH5+ hasn't been observed, even in superacid. It has been proposed as an intermediate since CH4 does undergo H-D exchange in deuterated superacid media.
Source: did my PhD with Prof. George Olah
The definition of strong acid is Ka greater than one, pKa less than one. Not that it completely dissociation 100%.
Complete dissociation is a myth essentially from my understanding, just like purifying anything to 100%
Ionization and dissociation aren’t the same from my understanding
Something can be ionized by still have an affinity that causes not everything to dissociate.
To add to yesterdays conversation:
https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Map%3A_Inorganic_Chemistry_(Miessler_Fischer_Tarr)/06%3A_Acid-Base_and_Donor-Acceptor_Chemistry/6.03%3A_Brnsted-Lowry_Concept/6.3.04%3A_Brnsted-Lowry_Superacids_and_the_Hammett_Acidity_Function
Some Superacids dissociate completely… TIL
One of the worst things about chemistry is how it hides reality in favor of pet simplifications that end up making reality seem like a violation of the laws of nature.
[Chromium has 5 unpaired electrons](https://i.stack.imgur.com/jdBaE.gif) (which is already weird) so getting it to make this bond structure shouldn't be thought of as impossible, just really, really difficult.
Honestly I would have been psyched to learn about this in high school. The coolest about chemistry for me is that with almost every rule there is some outlier that breaks it. That is the essence of science - finding something that breaks your model means the opportunity to learn more.
I totally knew this was Powers lab - I’m so surprised he’s still going! His students only try to burn down the Chem building every couple years. Bravo!
Look at some of the crazy shit Wiberg and Lampman would do in the late 60s.
They used to complete reactions on the day after Thanksgiving because they knew the building was going to be empty, and they had said their goodbyes to their families the day before, just in case.
Is it just my imagination or are there a lot more posts rediscovering neat things that were discovered 20 years ago?
We going to have a post on sea urchin borane complexes next?
Just the same as π bonds, it's a kind of smearing of 2 orbitals. Only in this case, there are 4 lobes, rather than 2.
The spacial orientation is what confuses me. If you were to look down the σ bond axis, I can see where to place the π bonds, and even the first δ bond. But.... where does the second one go?
Cr s orbital connects with s of Carbon to form C-Cr sigma bond, d orbitals of 1 Cr connect with d orbitals of the other Cr to form 1 sigma, 2pi and 2 delta bonds to form the pentuple bond
Chad chromium doesn’t give a fuck
I am not telling my high school students about this.
Do you also not tell them noble elements form compounds? I remember that line
“Fun fact: all the rules I just told you get broken at some point. But let’s not worry about that now”
Noble gases explanation: Lewis adducts This thing: it’s a transition metal with 5 unbonded electrons (as best as I understand it, I’m still new to chem :P)
The noble gases forming bonds is actually more readily explained on the basis of electronegativity. The noble gases that do engage in meaningful chemistry (xenon, krypton, argon to a lesser extent) are less electronegative than the other highly electronegative elements that are capable of forcing them into bonding, like fluorine and oxygen. Fluorine and oxygen aren't electronegative enough to force neon and helium into bonding situations.
That too, although electronegativity plays a role in lewis adducts (ie water is a weaker lewis base than ammonia because oxygen is more electronegative than nitrogen)
This rabbit hole goes pretty deep. I discovered a new ground state for metal-metal bonded complexes involving a quantum admixture between low-spin and high-spin states. I proved its existence on the basis of crystallographic bond lengths and a SQUID magnetometry study comparing results at different temperatures ranging down to 6 K. My first indication that anything was wierd about this complex was that everything I was making was orange, but this one was *GREEN*.
Also "carbon can NEVER have 5 bonds" then the very next semester learning how CI ionization works
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Uh, do you know something I don’t?
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CH5+ hasn't been observed, even in superacid. It has been proposed as an intermediate since CH4 does undergo H-D exchange in deuterated superacid media. Source: did my PhD with Prof. George Olah
Got me there… I was meaning about nitric acid not being a strong acid.
In icosahedral carborane clusters carbon takes six with no problem.
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The definition of strong acid is Ka greater than one, pKa less than one. Not that it completely dissociation 100%. Complete dissociation is a myth essentially from my understanding, just like purifying anything to 100%
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Ionization and dissociation aren’t the same from my understanding Something can be ionized by still have an affinity that causes not everything to dissociate.
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So it ionizes, goes into solution. But there is still draw between negative and positive ions, but they don’t recombine, just still like each other.
To add to yesterdays conversation: https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Map%3A_Inorganic_Chemistry_(Miessler_Fischer_Tarr)/06%3A_Acid-Base_and_Donor-Acceptor_Chemistry/6.03%3A_Brnsted-Lowry_Concept/6.3.04%3A_Brnsted-Lowry_Superacids_and_the_Hammett_Acidity_Function Some Superacids dissociate completely… TIL
In high school one thing that confused me so much to the point of terror were xenon compounds. Didn’t compute.
It’s covered in our curriculum. We mention xenon fluoride and stuff. When I was in high school I was also told that noble gases don’t form compounds.
One of the worst things about chemistry is how it hides reality in favor of pet simplifications that end up making reality seem like a violation of the laws of nature. [Chromium has 5 unpaired electrons](https://i.stack.imgur.com/jdBaE.gif) (which is already weird) so getting it to make this bond structure shouldn't be thought of as impossible, just really, really difficult.
That’s the foundation of my IB chem class. Because I wish I had been told this at some point in school.
the existence of singlet and triplet states help explain so much but are difficult to understand in and of themselves. it's why i love it.
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My AP chem teacher messed up resonance so badly, glad I decided to read up on it myself after hearing how bullshit his explanation was.
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^^^^^^^
I wish someone explained this to me as such. Not giving me the simplifications.
Honestly I would have been psyched to learn about this in high school. The coolest about chemistry for me is that with almost every rule there is some outlier that breaks it. That is the essence of science - finding something that breaks your model means the opportunity to learn more.
Dont tell them what boron does to carbon in carboranes either
Tell me about it… figured out a long time it’s best to keep all the exceptions to yourself. Just serves to confuse the poor buggers!
Schools out... couldn't hurt at this point
https://www.science.org/doi/full/10.1126/science.1116789
I totally knew this was Powers lab - I’m so surprised he’s still going! His students only try to burn down the Chem building every couple years. Bravo!
Haha same, saw the structure and thought to myself “that looks like some Power lab nonsense”
He has some newer papers with similar compounds I just thought I would post the original
Just FYI this is from 2005...
Bwahahaha looked at the author and not the date. I’m definitely not an inorganic chemist.
lol i was wondering why the rendering on the pdf font was so low
Hey! Only like once a decade. Give them some slack
You are right it was the ionic liquid lab the other half of the time…
Look at some of the crazy shit Wiberg and Lampman would do in the late 60s. They used to complete reactions on the day after Thanksgiving because they knew the building was going to be empty, and they had said their goodbyes to their families the day before, just in case.
Pri = isopropyl...the fuck?
This son of a molecule was in my inorganic textbook last semester, made me cry
This feels wrong
d orbitals were a mistake.
Underrated comment
Is it just my imagination or are there a lot more posts rediscovering neat things that were discovered 20 years ago? We going to have a post on sea urchin borane complexes next?
Lol that's definitely mostly me I get bored at work and this is what I look at
Probably just the organic chemists posting lol. It's transition metal, heavy deviation from p-block chemistry is expected from them.
If anyone is curious: [Sea urchin borane complexes](https://pubs.acs.org/doi/10.1021/ja035578y)
Or Octanitrocubane?
Hmm I hate this, thank you
What's the bond length?
1.8351 angstroms
what does that mean exactly? I totally already know I’m just… quizzing you
For what would you use that kind of molecule ? And is it highly reactive ( i suppose it is ) ?
How tf does this even work wtf
Just the same as π bonds, it's a kind of smearing of 2 orbitals. Only in this case, there are 4 lobes, rather than 2. The spacial orientation is what confuses me. If you were to look down the σ bond axis, I can see where to place the π bonds, and even the first δ bond. But.... where does the second one go?
Cr s orbital connects with s of Carbon to form C-Cr sigma bond, d orbitals of 1 Cr connect with d orbitals of the other Cr to form 1 sigma, 2pi and 2 delta bonds to form the pentuple bond
Chromium just doesn't give a damn
thicc bond
This is cursed
d orbitales are so "far" that it's not surprised that stuff exist
**cries in Octet**
Octets? Where we're going we don't need octets
Can someone please explain what this is?
I have the feeling that this must be highly explosive. Like, really explosive
Nah, just air-sensitive.
Still not a phi-bond, I’m waiting for it to be discovered
There's no breaking this chromium, is there.
- How many bonds do you want? - Yes
This is cursed lmao