SYNTHESIS AND REACTIVITY TOWARDS DIOXYGEN OF SOME MANGANESE(II) COMPLEXES OF TERTIARY-AMINES - CRYSTAL-STRUCTURES OF [(MNI(2)(NET(3)))(2)],[(MNI(2)(NPR3N))2] AND[NHME(3)][MNI(3)(NME(3))]

Some manganese(II)-tertiary amine complexes of stoichiometry MnX(2)(NR (3)) have been prepared for the first time. Magnetic susceptibility an d X-ray crystallographic studies on [Mnl(2)(NR(3))] (R=Et or Pr-n) ind icate that the complexes have a dimeric structure, in contrast to the analogous tertiary phosphine complexes which are polymeric. The crysta l structure of [NHMe(3)][Mnl(3)(NMe(3))] which contains a mononuclear manganese site has also been determined. This complex is postulated to arise from reaction of a solution of [Mnl(2)(NMe(3))] with trace quan tities of moisture. The reaction of the complexes with dioxygen has al so been examined: [MnBr2(NMe(3))] shows no interaction, [Mnl(2)(NEt(3) )] absorbs 2 mol of dioxygen per mol of complex, whereas [Mnl(2)(NPr3n )] absorbs only 1. In contrast to the analogous tertiary phosphine com plexes, the [Mnl(2)(NR(3))] complexes do not exhibit reversible bindin g of dioxygen.