Student creates powerful catalyst from potassium • Hacker News Board

Re: Student creates powerful catalyst from potassium

#31

Post by kbetz » Thu, Apr 23, 2015, 6:51 AM UTC

jedharris wrote: post #14

jedharris wrote: post #13

The read cube link doesn't work for me. I kind of get the weirdness of the result and the usefulness of silanes. But nothing explains what you have to do with potassium tert-butoxide to get this to work. That may be why some comments remark on the irritation -- no specifics. If I could access the paper I probably still could not understand the process but maybe someone could translate it into lay speak. Also the pote…

The interviews are helpful but only deepen the mystery. They say that the reactions are so easy they can be carried out at room temperature in introductory college chemistry (albeit at Cal Tech). And potassium tert-butoxide is apparently cheap and common. So what exactly did this team discover? Apparently the basic recipe can be varied to cover a huge range of applications. What are the key new ideas common to all th…

So as some other comments say, we discovered that this reaction was a thing at all! Once you put everything together, it happens very simply, in an easy setup, but no one had put together this setup because it's so unlikely and, according to old chemical knowledge, impossible. It's hard to describe just how much this goes against the grain of 100 years of chemical history, which all tell us that precious (transition) metal catalysts are absolutely necessary for these types of seemingly difficult transformations. This is like - to make a complicated pastry with layers and bubbles and flakes, it's a crazy bakery process, right, complicated and most people can't do it. But what if I told you to make the most complicated pastry, all you had to do was add salt and stir it up in a big bowl and poof - your pastry would be there? You'd laugh at me and say I didn't know anything about pastry-making.

The thing is, in this case, it's right - a potassium salt can indeed do this, which goes against this big assumption that chemists have been making for a very long time: that transition metal catalysts (the middle block of the periodic table) are the ONLY things that can do this type of chemistry.

So to answer your last question, the key new idea is "earth-abundant catalysis" - or the fact that we can do these complicated reactions with very, very simple, cheap, and common reagents - maybe the way that Nature itself does chemistry!

Re: Student creates powerful catalyst from potassium

#32

Post by ackalker » Thu, Apr 23, 2015, 7:15 AM UTC

minthd wrote: post #10

subnaught wrote: post #7

Earlier quoted context omitted.

An organosilane is basically any molecule with a Si-C bond. This reaction step creates the Si-C bond, so you could (in theory) use it to prepare any organosilane by starting with the correct Si- and C- containing fragments. Organosilanes currently find wide use in industry as hydrophobic coatings, adhesion promoters, and as useful intermediates in drug synthesis. It's a little hard to describe just how unbelievable t…

So what will happen now ? since we no longer know how (some) catalysts work, will this start a race of scanning materials(i.e. combinatorial chemistry) to find catalysts ?

> [...] will this start a race of scanning materials(i.e. combinatorial chemistry) to find catalysts ?

It will be like the race to find high-temperature superconductors all over again :-)

Re: Student creates powerful catalyst from potassium

#33

Post by biot » Thu, Apr 23, 2015, 7:36 AM UTC

refurb wrote: post #26

jedharris wrote: post #18

Earlier quoted context omitted.

Not being a bench chemist I have no sense of what "the reaction" is, even looking at the paper. Could you describe it?

Heteroaromatic silanes (rings made mostly of carbon but also include a non-carbon atom like nitrogen) are useful synthetic intermediates (you can use them to make other molecules). In the past, you usually made them using precious metal catalysts (really expensive metals like rhodium; the reactions are easy to screw up). The metal atom basically inserts between the ring and a hydrogen (the outside of the rings are co…

Sounds a bit like how Feynman diagrams changed finding solutions to quantum problems from lengthy, complex math equations into simple doodles.

Re: Student creates powerful catalyst from potassium

#34

Post by mijoharas » Thu, Apr 23, 2015, 9:22 AM UTC

subnaught wrote: post #7

iaw wrote: post #2

Does anyone have insight into what type of silicon product they were creating and it's usefulness (if any)? I'm not sure if I missed it in the article or if it just wasn't there.

An organosilane is basically any molecule with a Si-C bond. This reaction step creates the Si-C bond, so you could (in theory) use it to prepare any organosilane by starting with the correct Si- and C- containing fragments. Organosilanes currently find wide use in industry as hydrophobic coatings, adhesion promoters, and as useful intermediates in drug synthesis. It's a little hard to describe just how unbelievable t…

Thank you!

I have to say, I'm all for making science articles more accessible, and I like that science journalism is more widely reported, but it really annoys me when an article both doesn't go into the technical details in any depth, and doesn't provide a noticeable link to the primary source.

Re: Student creates powerful catalyst from potassium

#35

Post by jedharris » Thu, Apr 23, 2015, 2:54 PM UTC

kbetz wrote: post #29

jedharris wrote: post #15

Earlier quoted context omitted.

OK, found a library with the subscription, and the key sentence in the paper seems to be: We observed that the combination of a bulky basic anion (that is, Ot-Bu, trimethylsilanolate or bis(trimethylsilyl)amide) and, importantly, a potassium countercation led to the desired C–Si bond formation. But I don't understand it at all. Lay speak translation needed.

Hi there, I'm Kerry - one of the researchers who wrote the paper. Basically, you have a molecule with a bunch of carbons bonded to hydrogens - like R-C-H (where R is the rest of your molecule). Then you mix in our catalyst (K-OtBu, the potassium tert-butoxide catalyst) and a silicon compound (let's say Si-H) and then stir it up, and you get your final product: R-C-Si-H! A very simple explanation for what is no doubt…

That really helps. Thanks very much.

Re: Student creates powerful catalyst from potassium

#36

Post by jedharris » Thu, Apr 23, 2015, 2:56 PM UTC

refurb wrote: post #26

jedharris wrote: post #18

Earlier quoted context omitted.

Not being a bench chemist I have no sense of what "the reaction" is, even looking at the paper. Could you describe it?

Heteroaromatic silanes (rings made mostly of carbon but also include a non-carbon atom like nitrogen) are useful synthetic intermediates (you can use them to make other molecules). In the past, you usually made them using precious metal catalysts (really expensive metals like rhodium; the reactions are easy to screw up). The metal atom basically inserts between the ring and a hydrogen (the outside of the rings are co…

Thanks! The description of the old complex way was helpful.

Re: Student creates powerful catalyst from potassium

#37

Post by jedharris » Thu, Apr 23, 2015, 3:03 PM UTC

jedharris wrote: post #13

The read cube link doesn't work for me. I kind of get the weirdness of the result and the usefulness of silanes. But nothing explains what you have to do with potassium tert-butoxide to get this to work. That may be why some comments remark on the irritation -- no specifics. If I could access the paper I probably still could not understand the process but maybe someone could translate it into lay speak. Also the pote…

These replies are great and the picture is getting clearer, but now I wonder... The linked article describes Anton Toutov as struggling to get the basic reaction figured out, being ready to give up, finally getting it to work well, etc. But this doesn't fit the underlying simplicity of the reaction. Kudos to Anton for noticing the oddity and figuring out what was going on, but was there really a heroic struggle or was that journalistic license?