The reactions of the three
tritolylphosphines (ortho, meta, and para) with the metal hexacarbonyls, M(CO)6
(M = Cr, Mo, W), have been investigated under a variety of conditions of
temperature, ultraviolet irradiation, and molar ratio. The products were of the
general formulae M(CO)5L and cis and trans M(CO)4L2
[L = tri-tolylphosphine] although not all the tetracarbonyl complexes could be
prepared. Infrared and nuclear magnetic resonance spectra of these compounds
showed interesting trends as the ligand was varied. ��� In addition, a novel series of derivatives
with tri(o- tolyl)phosphine (pot) has been isolated, which on the basis of
infrared, N.M.R., and mass spectral data are formulated as π- (pot)M(CO)3.
��� The nature of the above reactions and the
properties of the products are explained in terms of an argument based on
steric effects.