White City is a small area in west london created as an exhibition site in 1908, morphing over the years into an Olympic games venue, a greyhound track, the home nearby of the BBC (British Broadcasting Corporation) and most recently the new western campus for Imperial College London. ^♣ The first Imperial department to move into the MSRH (Molecular Sciences Research Hub) building is chemistry.

Previously, I looked at models of how ammonia could be protonated by water to form ammonium hydroxide.

The previous post explored the structural features of amides. Here I compare the analysis with that for the closely related thioamides. Here is the torsional analysis around the C-N bond. The “diff” (difference) is that almost all the hits are concentrated into angles of 0° or 180°; the twist about the C-N bond from co-planarity is much less if S is present.

The π-resonance in amides famously helped Pauling to his proposal of a helical structure for proteins. Here I explore some geometric properties of amides related to the C-N bond and the torsions about it. The key aspect of amides is that a lone pair of electrons on the nitrogen can conjugate with the C=O carbonyl only if the lone pair orbital is parallel to the C-O π-system.