AMINE COMPLEXES OF TUNGSTEN(II) AND MOLYBDENUM(II) - M(NH2R)CL2(PMEPH2)3 AND M(NH2CH2CH2NH2)CL2(PMEPH2)2

Addition of primary amines or ammonia to solutions of WCl2(PMePh2)4 (1 ) or MoCl2(PMePh2)4 (6) results in the formation of [M(NH2R)Cl2(PMePh2 )3] (M=W (2), Mo (7); R=H, Me, (n)Pr, (i)Pr, C6H11, CH2CF3, or CH2CH=C H2). With larger secondary amines, no reaction is observed, except for a transient adduct of aziridine. Ethylenediamine substitutes for two phosphines, forming M(en)Cl2(PMePh2)2, but further substitution has no t been observed even in neat ligand. Reactions of [WCl2(CH2=CH2)2(PMeP h2)2] (4) with NH2Me and NH2nPr yield equilibrium amounts of amine-eth ylene complexes [W(NH2R)C]2(CH2=CH2)(PMePh2)2] (5) plus ethylene. The characterization of these compounds by paramagnetic NMR, IR, and mass spectra is described. The amine complexes do not lose hydrogen to form imido complexes, in contrast to the analogous reactions of alcohols a nd thiols with 1 which yield oxo and sulphido complexes. This appears to be related to the lower acidity of amines versus alcohols and thiol s.