C-13 NMR AND SCCCMO STUDIES ON SUBSTITUTED BENZOPHENONETRICARBONYLCHROMIUM COMPLEXES

13C NMR studies on benzophenonetricarbonylchromium and its p-F, p-Cl and p-OCH3 derivatives, with the substitutents on the uncomplexed rings, show a small substituent effect on the complexed ring and on the carbons of the Cr(CO)3 group. The SCCCMO calculations show π-electron donation from the ring to the metal but greater σ-electron back-donation which leaves the ring more negatively charged than before complexation. The chromium atom is more positively charged than it is in benzenetricarbonylchromium. The trends is calculated CO bond orders are in agreement with the trends in CO infrared stretching frequencies. © 1979.