Group VI Metal Complexes of Carbon Monoxide and Isocyanides

The proliferation of group VI metal carbonyl complexes continued in the primary literature during the 2006–2020 period covered by this contribution. The general robustness of group VI metal tetracarbonyl and pentacarbonyl fragments lend themselves to their incorporation into complexes with a wide variety of ligands, containing a plethora of different group VI metal–element bonds. The classical application of group VI metal carbonyl fragments as electronic reporters of ancillary ligand donor ability via infrared spectroscopy remains a contemporary motivation for the preparation of these complexes. The exploration of group VI metal isocyanide complexes enjoyed a resurgence during 2006–2020, and the exciting fundamental discoveries disclosed during this period promise further fruitful work in this area.