Reactions of molybdenum hexacarbonyl with schiff's bases

Abstract

Reaction of molybdenum hexacarbonyl with potentially tetradentate Schiff's bases gave complexes dicarbonyl-NN′-ethylenebis(salicylylaminato)molybdenum(II), (I)[from NN′-ethylenebis(salicylideneimine) and also NN′-ethylenebis(salicylylamine)], dicarbonylaminobis-N-ethylenesalicylylaminato)molybdenum(II) hydrochloride, (II)[from aminobis(N-ethylenesalicylideneimine) hydrochloride], and hexacarbonyltris[bis(acetylacetone)ethylenedi-imine] dimolybdenum(0), (III)[from bis(acetylacetone)ethylenedi-imine)]. With 2,2′-bibenzothiazolinyl decomposition of the ligand occurred through abstraction of sulphur by molybdenum. During the reactions which gave complexes (I) and (II) hydrogenation of the CN bonds of the Schiff's bases occurred. I.r., u.v., and visible spectra and magnetic susceptibilities of the complexes are reported. All three complexes are diamagnetic. Complexes (I) and (II) are considered to be mononuclear, distorted octahedral with cis-(CO)₂ groups and complex (III) to be binuclear with cis-(CO)₃ groups, with neutral Schiff's base ligands bound through nitrogen atoms only with one Schiff's base as a bridging ligand. None of the complexes was effective as a catalyst for the reduction of dinitrogen although hydrogenation of the CN bonds of the Schiff's bases has some similarity to a proposed mechanism of nitrogen fixation.