Aromatic 5-silicon rings synthesized at last

3 days ago (cen.acs.org)

>Move over cyclopentadiene anion—there’s a new five-membered aromatic ring in town, and this one is made of silicon.

CHEM-Es are build a little different from the rest of us.

  • Chemists really. Chem-E’s basically just play IRL Factorio at work. The graphs in Factorio look almost exactly like OSI PiSoft charts, which basically every chemical plant uses.

  • Cyclopentadiene is a great molecule - it can form 'metallocene' compounds where two cyclopentadiene (Cp) rings 'sandwich' a metal ion between them:

    https://en.wikipedia.org/wiki/Metallocene

    Like Cp--M--Cp where the '--' are an unusual kind of 'bond' which is somewhat like five carbon-metal bonds, although I'm sure there is a more accurate orbital description of the interaction.

  • "The average person probably only knows the formulas for olivine and one or two feldspars" (https://xkcd.com/2501)

    • Perfect! I read this “heart-warming” overview of two papers in Science and learned zero about why this is of any significance. The discovery is significant but I had to probe Opus 4.6 to find out why.

      The personal focus is a distraction. It would be great if science writers could focus on the science and significance of the advance.

  • Nah, this is just a strict chemical synthesis problem, no need for the engineers yet, until you want to make ten thousand tons of the stuff.

Any possible applications?

  • > Iwamoto and Scheschkewitz say pentasilacyclopentadienides could be ligands for catalysts and materials.

    • The review should have expanded on this at a practical level even mom and dad could understand—the standard “better life through chemistry” angle.

    • Sounds like it could improve the production efficiency of glyptal-impregnated, cyanoethylated bushings for turbo-encabulators!

So what was their aroma like?

So, we have a chance to reduce our usage of volatile hydrocarbons. Silicon-based chemicals should not burn as easily as CH-based ones.

  • No, it's a super weird molecule that is big, expensive to make and probably form a solid. It can not replace solvents like benzene.

    The weird structure of the electrons in the silicon cycle may be useful as a catalyst(or not, it's too early to be sure). Imagine it is like the Platinum in the car exhaust, not the solvent in the paint remover.

  • This particular silicon compound is unlikely to help much in that direction.

    On the other hand, silicone resins and elastomers are already in widespread use in applications where resistance to high temperatures or burning is required (silicone =/= silicon, the former coming from silic-on + ket-one, a name based on a wrong hypothesis).

    However, their mechanical resistance is usually modest, so if that is important they must be used either in combinations with other materials or reinforced, e.g. with glass fiber.

    They are also more expensive than hydrocarbon-based plastics, so they are typically used only where strictly necessary.