Proton Chemical Shift in HCo(CO)4

Abstract

The anomalous high‐field chemical shift observed in general for H bonded to a heavy metal has been calculated in the localized diatomic approximation for the CoH bond in HCo(CO)₄ with the use of the theory of Kern and Lipscomb, valid for a light atom bonded to a heavy atom. It is shown for the first time that reasonable agreement with experiment is obtainable at a bond distance corresponding to a normal covalent bond, and that, aside from the electron around H, the major contribution to the high‐field shift comes from the electron populations in the large and diffuse 4s and 4p orbitals of Co.