title: The vibrational spectra of the cyanide ligand revisited. Bridging cyanides.
abstract: The nu(CN) vibrational spectra of cyanide groups bridging two metal atoms present a confused picture. Factors relevant to the interpretation of the available data are reviewed. Some mechanisms for frequency change, relative to the corresponding terminal species, are made more quantitative than previously described, and others are highlighted for the first time. The kinematic effect is much less important than previously assumed. It seems that an effect responsible for the major part of the frequency increase upon bridging commonly observed is the cation electric field, together with concomitant relaxation (the IVSE model). However, a contribution may well come from the change in the sigma bonding in the CN unit.
authors.affiliation: School of Chemical Science and Pharmacy, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Sidney F A
authors.initials: SF
authors.lastname: Kettle
authors.forename: Eliano
authors.initials: E
authors.lastname: Diana
authors.forename: Enrico
authors.initials: E
authors.lastname: Boccaleri
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Stanghellini
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D003486:Cyanides / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D003432:Cross-Linking Reagents; D003486:Cyanides; D008024:Ligands