Reactions of chromium and molybdenum carbonyls with bis-(salicylaldehyde)ethylenediimine schiff-base ligand

Interaction of bis-(salicylaldehyde)ethylenediimine, salenH2, with M(CO)6 (M = Cr, Mo) in air gave M(O)(salen) complexes. Magnetic studies show that the metal exists in the +4 oxidation state. Cr(CO)6 reacted with salenH2 under reduced pressure to yield the dicarbonyl derivative Cr(CO)2(salenH2). Reactions of M(CO)6 with salenH2 in the presence of a secondary ligand L (L = H2O, pyridine) resulted in the formation of the square pyramidal complex M(L)(salenH2). UV-Vis spectra of the complexes exhibited visible bands due to metal-to-ligand charge transfer. Structures for the complexes are proposed on the basis of spectroscopic studies.