ortho-Metalation reactions. Part I. Reactions of azobenzene with some metal carbonyl complexes of sub-groups VI, VII, and VIII

Reactions between azobenzene and [M2(CO)10],[MeM(CO)5](M = Mn or Re), [Mn(CO)4PPh3]2, [(π-C5H5)M(CO)2]2(M = Fe or Ru), [MeFe(CO)2(CO)2(π-C5H5)] and [(π-C5H5)Ni(CO)]2 have afforded (phenylazophenyl-C2,N)′-complexes of the respective metals, often in high yield. Reactions with [Mo(π-C5H5)(CO)3]2 and [(CO)3MeMo(π-C5H5]) are more complex, the initially formed [(π-C5H5)Mo(CO)2C6H4N:NPh] with an excess of the reactants rapidly forming products containing o-semidine ligands.