IONIZATION POTENTIAL OF SUBSTITUTED BENZENE CHROMIUM TRICARBONYL COMPLEXES

The ionization energies of ring-substituted benzene chromium tricarbonyls, measured by electron impact mass spectrometric methods, are presented and discussed. Differences were found between these values and those obtained by the CT-method. As a first approximation, a linear correlation existsbetween the v(CO) force constants of the complexes and their ionization potentials, but no simple connection with the I.P. values of the free aromatic ligands could be found. The ionization energies of the complexes reflect the donor-acceptor capabilities of the ligands. The changes in the electronic structure of the aromatic ligands upon complex formation are discussed also. © 1969.