Last year, this article[cite]10.1038/nchem.2716[/cite] attracted a lot of attention as the first example of molecular helium in the form of Na 2 He. In fact, the helium in this species has a calculated ‡ bond index of only 0.15 and it is better classified as a sodium electride with the ionisation induced by pressure and the presence of helium atoms.
I discussed the molecule the molecule CH3F2- a while back.
About 18 months ago, there was much discussion on this blog about a system reported by Bob Pascal and co-workers containing a short H…H contact of ~1.5Å[cite]10.1021/ja407398w[/cite]. In this system, the hydrogens were both attached to Si as Si-H…H-Si and compressed together by rings.
This is taking place in the idyllic surroundings of the Niederwald forest, Rüdesheim, Germany. Here I highlight only aspects of the first three talks.
One thing leads to another. Thus in the previous post, I described a thermal pericyclic reaction that appears to exhibit two transition states resulting in two different stereochemical outcomes.
A feature of a blog which is quite different from a journal article is how rapidly a topic might evolve. Thus I started a few days ago with the theme of dicarbon (C 2 ), identifying a metal carbide that showed C 2 as a ligand, but which also entrapped a single carbon in hexa-coordinated mode.
A conjugated, (apparently) aromatic molecular trefoil might be expected to have some unusual, if not extreme properties. Here some of these are explored. The first is the vibrational spectrum. With 144 atoms for this molecule, it has 426 vibrational modes, but one is highlighted below. This is the mode that moves the atoms in accord with the Kekulé resonance. If real, this mode resists such alternation.