Infrared studies of amine, pyridine, and phosphine derivatives of tungsten hexacarbonyl

Article abstract of DOI:10.1021/ic50055a026

Seventeen complexes, LW(CO)₅, where L = amine, pyridine, or phosphine, have been prepared and examined in the C-O stretching region of their infrared spectra. The C-O stretching frequencies and force constants in the amine, pyridine, and phosphine series decrease as the basicity of L increases, and the magnitude of this decrease is virtually the same for all three groups of ligands. The results suggest that W-L π bonding, even for the phosphines, need not be invoked to explain the C-O stretching frequency shifts in these metal carbonyl complexes.