2000 Alcan Award Lecture Adventures in organometallic NMR: steric restraints, slowed rotations, and skeletal rearrangements

The structures and NMR fluxionality of a wide variety of organometallic complexes (including tetrahedral cluster cations and systems of the type (C n R n )ML 3 , where R = Et, Ph) are discussed. Barriers to tripodal and peripheral substituent rotations are reported, and the relevance of correlated rotations to molecular machines is outlined. Haptotropic shifts in (cyclopenta[def]phenanthrenyl)ML n and (cyclopenta[l]phenanthrenyl)ML n complexes …