How chemists create "SUPERBENZENE" (Kekulene) | Organic chemistry, synthesis & reaction mechanisms
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- Опубликовано: 9 июл 2024
- 😎 Benzene is the classic example of aromatic stability with n=1 for the Hückel rule of 4*n+2. Big brain chemists also will know more exotic examples for aromaticity (e.g., the cyclopropyl cation). But have you heard of super-aromaticity? In this video, we will explore the classical (Staab, Diederich) and modern (Perez) synthesis of Kekulene.
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00:00 Super-benzene and aromaticity
02:16 Super-aromaticity in Kekulene
04:22 Old-school Kekulene synthesis and characterization by Staab and Diederich
09:40 Modern synthesis and characterization by Perez
Main papers: Benzenoid versus Annulenoid Aromaticity: Synthesis and Properties of Kekulene; onlinelibrary.wiley.com/doi/1...
Cycloarenes, a New Class of Aromatic Compounds, I. Synthesis of Kekulene; chemistry-europe.onlinelibrar...
Revisiting Kekulene: Synthesis and Single-Molecule Imaging; pubs.acs.org/doi/10.1021/jacs...
Some recommended books on organic synthesis:
- Clayden, Greeves, Warren; Organic Chemistry (basic organic chemistry knowledge)
- Wyatt, Warren; Organic Synthesis: The Disconnection Approach (excellent introduction to retrosynthesis)
- Kurti, Czako; Strategic Applications of Named Reactions in Organic Synthesis (extensive toolkit of functional group reactions and applications thereof with common conditions)
- Nicolaou et al; Classics in Total Synthesis 1-3 (the ultimate total synthesis trilogy)
- Nicolaou; Molecules That Changed the World (the world's most important molecules and their impact on everyday life)
- Carreira, Kvaerno; Classics in Stereoselective Synthesis (compilation of the groundbreaking methods of stereoselective synthesis and application to synthesis of stereochemically complex structures) 
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Thank you!
the fact that a molecule has "kek" in its name is just... wonderful
Isn’t it just, it’s like a universal justice has been fulfilled
Kek.
It's because the structure of benzene was proposed by Kekule
Praise the kek!
@Fresh Rutabaga we're a part of the few that actually knows lol
what if... supersuperbenzene! make a ring out of a bunch of these!
Id feel some overkill engineered high powered laser + high resolution AFM can blast holes into graphene and you "carve" out the rings of rings from the sheet that way lol
The c-c double bond length is 1.34 Å, and the single bond 1.54 Å, so the length of benzene from one side to the opposite one is 2.49Å. The length of super-benzene is roughly 8.64Å, so the scaling factor is 3.464. 2.49*3.464^18=1.3*10^10Å=1.3 m, so you would need 18 super's to make a life sized benzene.
Benzene all the way down
@@C4pungMaster graphine is benzene 🤔
Flip it vertically and stack them to make a torus.
I love to see that those polycyclic aromatic hydrocarbons get some attention, as well as Diederich, who contributed so much to this field! Well done!
He was a truly wonderful person. Tragic he passed away - but he will be fondly remembered.
i really like the fact that you show both modern and old school syntheses
5:44 That Swiss pronunciation caught me off guard.
The compounds covered on this channel are becoming increasingly exotic. And I love it.
Thanks man!
I've only taken ochem1 and my mind is blown! This synthesis is insane! Thank you for contributing this awesome content, and I hope the algorithm turns to favor you! Subscribed
What a kind comment! Thanks for your support 🔥
@@totalsynthesis fuck yeah bro! Surprised that the algorithm randomly finally gave me content that I loved! Hope this bodes well for your channel!
@@totalsynthesis I would never have found you but for the algorithm lol
Synthetic chemists is a truly gigachads of chemistry i think.
Great video! Another example of an unusual aromatic compounds are carbo-benzenes. Carbo-benzene is a carbo-mere of benzene and it's basically a C18 ring where you have an alternation of allene and alkyne fragments (in contrast to sigma and double bonds of benzene). This topic was developed by Prof. R.Chauvin and his group in Toulouse.
Looks sick 😂
These organic chemists are out of this world. True genius
I loved this video. In my organic chemistry 2 class when we started learning arenes and aromaticity that is when I had my "aha" moment ! I was so happy to see I knew before mentioned that the newer method looked an awful lot like diels-alder. Thanks for the upload!
small knowledge like this will help me when I get to organic chem. I do really love chemistry more than any other subject.
Thanks Chem Chad
I appreciate the discussion around the instrumentation.
How have I not seen your channel before?! I am a master's student in organic chemistry and I already know that I will love all of your videos! Keep up the good work :)
Welcome onboard! :) And good luck with your studies
first video ive seen from your channel, but it was very good! will be sure to stick around for more :)
Thanks - hope you binge watched all of them! 😂
how cool! I'd certainly think delocalization of all the electrons in the ring would make it more stable than 6 "islands of delocalization", wonder how stability of delocalization relates to the area it's spread throughout, and where's the cutoff when it's just too hard
Basically the C6 rings bring a great deal of stability over localized double bonds, everything beyond that has diminishing returns at best.
the pinnacle of onion rings chemistry.. awesome stuff and thanks for covering about it man!
glad to see you posting again brother
🙏
Fascinating ⚡️
thanks for your efforts, I thoroughly enjoy your content.
Appreciate it!
These videos are a gift. Thank you!
What an honor, thanks!
Anyone includes Clar's work in their presentation clearly knows what they're talking about. Kudos for an enjoyable but seminar-like video.
By the way I study the synthesis of carbon nanotubes and a lot of this is relevant to that problem and yet often ignored.
Super cool. Thanks!
If benzene is fun, then this is top kek!
And it's a really nice looking molecule.
Super interesting. I really appreciate all the work you put into this.
I sometimes look back in regret that I never got a break as an organic chemistry researcher.
Thank you!!
Yeah, me too. Now I'm a nobody accountant wishing I'd put more work in. Ey oh.
@@darrena2625 Personally still in chemistry (I teach it) but only at A-level, v.v.v far from the cutting edge of research.
Still, as an accountant the money is probably better - hopefully anyway.
@@kychemclass5850 agreed, being at the edge of a field might sound like a cool day dream but it can be as good to do something 'normal' and pursue the scientific understanding as an interest
I know nothing about chemistry, but it still was interesting to watch
Incredible work at a point in history with no computer assistance by God these folks are brilliant!
Facts! FYI I just uploaded a new video on a similarly cool topic
Great video as usual!
🙏
As a kid with a passion for chemistry, but only just getting into organics, this feels like 70% random stuff and 30% "well I understood something at least"
Great video btw!
Thanks man! Hope the random things are interesting!
I'm a working stiff in heavy industry but have just enough knowledge to get myself in trouble regarding the world of chemistry and I cought about 70% of the video thanks for explaining my knowledge
Wow! This is an awesome video. i
I know only the basics of the basics of organic chemistry, but seeing such highly complex synthesis and depth of organic chem. blows me away! It gives so much motivation to learn more about this field of science!
Apart from that, i adore and respect high-quality videos like this cause i can only imagine how much effort was put in it!
Edit: It might sound silly, but i really like when organic chem compounds "power up" like benzen and kekulene. I remember when I saw a simple alkane called 2,2-dimethylpropane (Neopentane), and i was blown away how it looks like if you would put one C atom instead of each H atoms in methane and i was like "This shit is powered up form of methane!" Goofy, i know, but that's how my brain works 😅
As always I am puzzled by your content. Interesting, educational and funny.
And you even made the effort to show all your sources.
Thanks man! Appreciate it
High school student, loved this video
Awesome!!
he's bacc :DD
Chemistry is so beautiful! Awesome video man!
I'm also curious, is there any practical uses for kekulene or is it just a "proof of concept" kinda thing?
More the latter :) proof of concept + insights for advanced theory
Cyclopropyl carbonium ion is interesting. I think I made this in the SN1 solvolysis of 2-adamantyl compounds. Only got the exo-protoadamantyl product, i.e. nucleophilic attack from only one side.
"If you thought drawing benzene was hard, let me introduce you to superbenzene"
i miss chemistry like this... we barely have any in chemical engineering courses sadly
Wow! Looks I've found amazing channel! Like and subscribe. That's not a shitty tiktok and not a letsplay, but just really informative content.
🙏
How do you get the benzaldehyde to combine with toluene? It doesn’t look very Aldol to me. Is that benzyl carbon electrophilic?
Has anyone made any quinone like versions of this molecule? Has anyone studied it for photoredox electron transfer?
I follow, barely. This is beautiful synthesis.. I always wonder about exotic side products that get thrown in the wash container never seeing NMR or mass spec
“Tar”
Majority agree polymerized tar. Minority are the ones I'm interested in.. Like the Comstock Lode throwing away tons of silver for ounces of gold, until the silver content was figured out and the mine purchased for pennies on the dollar.
I know the structure of benzene. Source? It was revealed to me in a dream
Love your channel. Are you in any way affiliated with ETH/do you study/work there?
Studied there :)
top kekule
How about drugs with an adamantane substituent? Many have some interesting common properties..
And who the heck built buckminsterfullerine?
Love your stuff my man
I hope NileRed sees this and make some for the fun of it 😀
Correct me if I'm wrong, but the hydrgenation procedure you show in 5:08 states that Raney-Nickel was used, not Pd / C?
I love the video by the way!
You're right - well spotted! They de-hydrogenated the Pschorr product with Pd/C to the dibenzoanthracene for analysis/proof of structure so that probably slipped into my drawing :)
RIP superaromaticity you were too based for this world man 😭
I cry every time
Why dont you make solid state NMRs with it?
I love Benny Zeine. The aroma of Phenylacetic acid as it couples with/against the cancer causing Benzene. Find how Peer reviewed info is golf clapping about Phenylacetic acid.
Those diagrams are a bit hard to understand. Some of the rings seen to have only one or two double bonds. Is there only one hydrogen on each of the outer carbon atoms with only two neighbors or do some have two hydrogens?
In the skeletal formula all carbons have '4 bond equivalents' and all hydogens bonded to carbon are implicit
What are the thermodynamic properties and phase diagrams of kekulene?
No clue my dude to what degree it has been investigated, probably the modern synthesis has some references regarding what is known about it to date
Perhaps it's more likely for there to be a net flow of electrons between 6 total bonds (in benzene) than through 18 (the inner path of theorized conjugation in kekulene). Maybe there are range limits to that kind of delocalization in nonmetals
I dont think its tied to probability of electron flow, and there are huge non-metal conjugated systems - the rationale for Clar rule is basef on deep quantum mechanics (there are some papers but I never looked into them)
@@totalsynthesis Interesting! I never took QM so I'm always more or less guessing where the electrons are. Luckily in my field it hasnt been a hugely relevant factor yet
Can one combine 6 Kekulene-molecules in a hexagonal shape to create a fractal „super-kekulene“ and what would be its traits?
You mean like a hexaphenylbenzene on steroids? Would be cool but probably super painful to create
@@totalsynthesis If this is what would be it’s name? My understanding of chemistry is very low, but the idea of kekulene being a kind of fractal benzene brought me to the idea of fractal chemistry in general, where you take 6 kekulene and build an even larger hexagon super kekulene from that, going up till you have some kind of polymer I guess.
There also is a book on fractal chemistry I saw on google, but it is extremely expensive.
Is Hückels rule easy enough to explain to someone who doesn't understand quantum mechanics?
If that's possible, if Hückels rule is explanable without too much, without an overdose, of quantum mechanics, then I would love to see a video, made by you, doing exactly that!
Will be super easy my dude. I usually don't do such videos but can make a short one if you want :)
@@totalsynthesis Please do
@@totalsynthesis Super easy?!? I mean the reason as to why 6 and 10 and 14 pi electrons will work, but not 8 or 12?! Without using difficult quantum mechanics?!! Well, if you can, PLEASE DO!!
@@fukpoeslaw3613 Well at some point you have to go into QM but I will try to explain simply :)
@@totalsynthesis Yes, there had to be some quantum physics involved, I'm still interested in an explanation though, but please take your time!
Bij voorbaat dank!
Can u make cubic graphite
So...get 2 molecules of kekulene and "stitch" them together into a torus - inner ring to inner ring, outer to outer.
Let me know when you complete that synthesis
@@totalsynthesis on a related note, maybe a list of "cursed syntheses" is possible for a future video
praise Kek
i like your funny words magic man
5:13 "2.4 kg of Raney Nickel" is not something I expected to read. xD
But is it possible to achieve the creation of the "Superkekulene"?
Actually... I will do a video on something similar in the future!
You know, Hexagons are the bestagons. Why? Because bees. Bees are the best and build only the bestagon, the hexagon. Now, I know what you're thinking. Bees build hexagons because they're hexapods with hexagon eyes. How could they do otherwise? Excellent point. But the humble bumble has an engineering problem to solve. She makes two things: honey and wax. The former to eat, and the latter to contain the former. To make but a little honey, she must visit a lot of flowers. And to make one unit of wax, she needs eight units of honey. Wax is costly for bees in flower terms, and honey is drippy in food terms, so to make a hive that contains the maximum honey while using the minimum wax is royally vital. Thus, a honeycomb conjecture. Which shape works best? To answer, we need to talk tiles. Tiling is covering a surface with a pattern of polygons. There's lots of options because there's lots of polygons. Even the regulars go on and on-agon. Now for bees picking patterns, the more complicated ones obviously use more lines than necessary. That's what complicated means. And thus a honeycomb of that tile would use more wax per honey. So sticking to the simple regulars, there are just three that tile tightly. Triangle, square, and hexagon. Pentagons are broken hexagons that leaves gaps. Same with Septagons. Octagons are alright, but they're no hexagon. Which leaves the tiling trio which tile differently. A square is a square of squares, which is a square and so on. Squares tile tidily by basically cheating, covering an infinite plane with an infinite number of parallel lines. Like, wow, that's what a plane is. Boring! Triangles pull the same trick, dividing themselves into infinite nothing. But not the hexagon! The only regular polygon to tile a plane without resorting to debasing self-division, unlike some squares I could mention. At least triangle is trying to be more geometrically interesting than square, teaming up a bit to... one, two, three, four, five, six. Wait, hexagon! The other shapes can't help it. They just want to be the bestagon. Even some of the irregulars, like rhombus, tile by hexagoning. Same with your triakis tiles, and deltoidal trihexagonals, and your, ah, kisrhombille, and floret pentagonals. Look, they're all just hexagons. Even Cairo tiles (poor pentagons) tile up as best they can do to form a lumpy hexagon. The rest just can't compete with the best. The hexagon, nobly indivisible, is the bestagon. Uhh, where were we? Oh right, honeycomb conjecture. Max honey. Min wax. Three options. Okay, yes, there's the circle. A shape defined by the least perimeter for the most area, but that only works when you need just one. Pack circles and this is the best they can do. Look at all that wasted space! And even if you pack the gaps, you still use more wax. And again the way these circles, arrange themselves... it's almost like... onetwothreefourfivesix hidden hexagon! Bees use the hexagon because no shape is better to create the maximum area for the minimum wall. And this min-max stat of hexagon is one of the many reason they show up everywhere. Including in the aforementioned bee's eyes. Each hexagon is a long tube that leads to the light-catching cells at the bottom. More light equals better vision and hexagons let the most light in using the least amount of wall. So why aren't your eyes hexagons? Au contraire mon ami, they are L'hexagone. Not on the outside, but on the inside. Your light catching cells are at the back of your eye, in a hexagonal grid for the same reason as bees. Max light, min wall. Your window to the world, is but through the hexagon. Does that not make it the bestagon? Okay maybe hexagons as a min-max-agon doesn't catch your fancy. Then how about a little mystery, oui? Let us travel to Saturn. Yes, the rings are attention-grabbing, but leave the equator, travel north and here lies the unexplained. The Great Hexagon of Saturn. Need something for scale? Well, here's the Earth. Oh, here's six Earths. Saturn's hexagon is pretty big. What is it? Well, you might be thinking it's a geological formation. An enormous basalt column like the smaller versions you find on Earth. But no. Saturn is a gas giant. There is no surface or geology to speak of. So the great hexagon is composed of shapeless clouds somehow keeping shape and changing color. It's a magnificent solar system mystery. And, while I'm no space archeologist, if I was looking for an alien-gifted monolith, on the most "look at me" planet, under a hexagon beacon with earth-sized sides, that's where I would start. After all, what aliens would want to make first contact with the nearby monkeys before they became enlightened to pursue the universal truth. Hexagon is the bestagon. From the largest down to the smallest. Say for example, this tiny snowflake I happen to have, that have six sides, as all snowflakes do. Gee, what could cause that to be? Let's zoom down to the atomic realm and see. When water molecules join together to make a flake, the sturdy shape they prefer is the hexagon. As more molecules join, they extend the flake fractally up. The beauty of the snowflake on the monkey scale, is but an extension of the hexagonal perfection on the atomic scale. Okay, yes, you will sometimes find snowflakes with twelve sides, but this happens when two growing snowflakes get stuck together, so it still counts. And the hexagon isn't just for snow, but for all ice 1H, which means basically all ice on earth. Yeah there's a little ice 1C which we don't talk about because it's made of cubes, and cubes are boring. And there's a bit of ice 9. No, don't touch that. But if there is ice in your drink, give thanks to the hexagon for keeping it cool. And it's not just water. Lots of atoms use hexagons because... (take a note) hexagons are the bestagons. Oh, using a pencil? Get ready to have your mind blown about the hexagon here too. The lead. Well, it isn't lead lead, it's carbon. And you know what carbon atoms think is the bestagon? The hexagon. Pencil graphite is a whole bunch of hexagonal carbons, and when they happen to be in a straight sheet, that's graphene. Which happens to be the strongest atomic material in the universe. Some of which is in that pencil. To tear a sheet of graphene apart, you would need a hundred times more force than to do with steel. Hexagon is strong-a-gon. This is because when hexagons come together, they form three-sided joints 120 degrees apart. This, for the least material, is the most mechanically stable arrangement. Pull on one joint, and the other two equally pull back, push in, and the other two are the most able and stable to resist. Now look anew at a tiling of hexagons and you see it is composed of nothing but these max stable joints, each arranged perfectly to help the others be stronger and stabler. This is another reason hexagons show up everywhere. The universe blesses stability in her physics, from those basalt columns, to bubbles which, as soon as they can, ditch their spheres to become as close to the hexagonal perfection as they can. That's so cool. Oh right, yes. So if your pencil lead contains some of the strongest material in the universe how can your write with it? Okay, okay. This is going to get even more exciting. While hexagons are super strong this way, they aren't super strong this way. On a small scale, that means your pencil can break off in layers to leave a mark. But on a big scale, hexagons can be flexable while keeping their strength. Which allows us to create some totally unreal materials. Print out a grid of hexagons in whatever, from aluminum to cardboard, make a little sandwich, and pow! You've got honeycomb paneling. A ridonkulously tear-resistant material that's also super light and flexible. It's used everywhere but particularly in aviation. Rockets need to be strong yet light. Same for aircraft. With wings that really can't tear but also need to bend. And only the magic of the honeycomb panel can do both as well. Give thanks to the hexagon for blessing our flight. And we still haven't yet discussed the most important application of the hexagon. Games! For centuries there has been great debate over boards, squares of hexagons? Spoiler... hexagons win. Square boards are the first thing an unenlightened species would think of. They look sensible and are easy to implement, but they are terrible, ineffective boards that cause spatial suffering. On a square board move horizontal or vertical once space and you've moved one space, but move diagonal and the distance is the square root of two spaces. Gross. Diagonals warp the distance pieces move. Square boards look even and tidy, but it's deceit. Their diagonals corrupting the meaning of space and time, and of course they must, because a square only has four true neighbors. Hexagons, however, have six which is more than four, which is better! And the distance from once space to the next is the same in every direction. One space. Just as it should be. If you're a game based on squares, I'm so sorry. But there is hope. With thought and effort, you can hexagon yourself into a better place. As we all should aspire to do, spreading order and hexagonal enlightenment for, hexagons are the bestagons. And now that you agree, with your eyes will see their six-sided perfection in all things. And you will say to yourself, as part of the order, hexagons are the bestagons.
Like a mad scientist writer's love child between Hunter S. Thompson and Charles Bukowsky with a dash of Burroughs.
Not bad.
Can you tell me what's the easy way to find out degree of unsaturation ?
chemistrytalk.org/degrees-of-unsaturation/
@@totalsynthesis thanks 😇
I understood most words.
😂
Wow.
How plausible would it be to make a version of kekulene where every radial bond is dative?
You mean a giant complex with metals in the inner rim?
@@totalsynthesis No, I mean replacing the C-C bonds between the 18-ring and the 30-ring with B-N dative bonds or something like that.
Is there a 6 ring "bigger-benzene"?
You mean like coronene?
Omg! 🤯
kekulene sounds like a anime power up for benzene
like a super saiyen benzene
Make a chain with kekulene links!
YEAH SCIENCE!!! 😃
At 2:30:
(1) benzene
(2) urchene
(3) nazene
wow
All that work and they couldn’t take a picture of the green crystals?? Come on!!!
I was literally joking about a benzene ring made of benzene rings a few months ago wtf i didnt know it was a real thing
Im working on another video (next one after my next one) that will blow your mind!
finally, i won't run out of car fuel
Watching this just because it may come in jee advanced.
When I saw the title I thought you were just being memetic or sth... then the name "Kekule" came up... I couldn't believe the name was actually "kekulene" until I actually googled it...
Topkek
Kekulene ring. Ok. Now make a ring out of the Kekulene rings. If that’s even possible, Idk man I just weld and fix stuff
Now I want to see it form sandwich compounds with chromium
😂
imagine how many nitro groups can fit on that, it would be so explosive
I like how you think sir
Bro's about to make nitrokek 💀
Two videos in a month; is it Xmas or what!
🎅🧪
Please, if you have not, find the book of aqaruis.
I wonder how many hydrogens and oxygens I can stick to this
Not every rings in kukulene is of benzene
Meine Kraftstof is B E N Z I N E
like I came here for the science, but just 10 seconds in the video I must click like for the meme
this must be the new "ligmasynthesis" every chemist has been talking about
Lmao
Nmmmm😊
KEK-benzene
Topkek
Is Keuken even more apolair than benzine? How is that possible?
Keuken = kekulene
benzine = benzene
(Dutch Spellingcontrole 😄)
I don't explain it in-depth (as I didn't think it's really striking) but an easy way to think about its polarity is to consider solubility in water: benzene: ~1.8 g/l; perylene: ~0.4g/L. Given kekulene is bigger (more rings), you can expect that it will be even worse.
@@totalsynthesis So if a(n) (apolair) molecule gets bigger, it's becoming more difficult to solve in water?
(If that's the reason I still have to think about it/imagine how that would work, because it's not readily clear to me)
@@fukpoeslaw3613 Yes. Let's say e.g., pentane vs. heptane solubility in water 0.04g/L vs. 0.003g/L. In general, if you only add carbons to an apolar molecule, it becomes less soluble. Dipoles are another major factor but they are not relevant for most symmetrical molecules or for molecules lacking any polar bonds (C-H and C-C is classified as non-polar)
@@totalsynthesis Oh, so size matters! I could have known if I had been studying better, but for me chemistry is only a hobby. Ok, thanks for your answer; and what I have to do now, is visualise/imagine the shit out of it until it makes sense. 😄
official fuel of kekistan
“A Chad version of normal Benzene”
Thats literally what it is!
@@totalsynthesis it’s absolutely a concise definition, hilarious in its accuracy! Appreciate your analogy.
Hehehehe kemist😎😎😎
😎
So now, the solution is crystal Clar.
ÆææææÆ
ANOTHER VIDEO?? :DDD
😎🔥🔥
:D
*MCWEENY*
is it yellow?😁
Greenish yellow apparently
Must look awesome
Mesomerie his father
Wait until he gets to know about fullerene
Brah I'm working on a video that will blow fullerene out the water