Mechanisms of Reactions of Open-Shell, Heavier Group 14 Derivatives with Small Molecules: n−π* Back-Bonding in Isocyanide Complexes, C–H Activation under Ambient Conditions, CO Coupling, and Ancillary Molecular Interactions†This Award Article summarizes, including more recent results, one of the themes of a lecture presented on March 26th, 2012, at the 243rd Chemical Society National Meeting American in San Diego, CA, in receipt of the 2012 Award in Organometallic Chemistry sponsored by the Dow Corporation.