Schiff base complexes derived from chromium, molybdenum and tungsten hexacarbonyls. Preparation, characterization and reaction with nitric oxide

Abstract The reactions of five Schiff bases (SB), viz.,N,N′- ethylenebis ( p -tolualideneimine) (SB 1 ),N,N′-ethylenebis( p -N,N- dimethylaminobenzalideneimine (SB 2 ), N,N′- ethylenebis (cinnamylideneimine) (SB 3 ), N,N′-ethylenebis(methyl- p -methoxyphenylketimine) (SB 4 ) and N,N′-ethylenebis(methyl- p -methylphenylketimine) (SB 5 ), with group VI metal carbonyls in aromatic hydrocarbon solvents have been studied. Mo(CO) 6 and W(CO), invariably gave cis-[(SB)M(CO) 4 ] (M = Mo and W) derivatives but Cr(CO) 6 yielded a mixture of [(SB)Cr(CO) 4 ] and the appropriate (arene)chromium tricarbonyl for SB = SB 1 , SB 2 and SB 4 and the only (arene)chromium tricarbonyl for SB = SB 3 and SB 5 . [M(CO) 5 (Ph 3 P)] (M = Cr and Mo) after reaction with SB give SB-bridged dinuclear [(Ph 3 P)(CO) 4 M(μ-SB) M(CO) 4 (Ph 3 P)] derivatives. Nitrosylation of cis -[(SB)M(CO) 4 ] (M = Cr and Mo) using NO-swept benzene has also been performed.