TRANSITION-METAL COMPLEXES WITH NEUTRAL AND DEPROTONATED MALONAMIDE

New complexes of the general formulae [M(LH(2))(2)Cl-2] (M = Mn, Fe, C o, Ni, Cu, Zn), [Mn(LH(2))(2)X(2)] (X = Br, I), [Cu(LH(2))(2)Br-2], [N i(LH(2))(2)X(2)] (X = Br, NCS, ONO2), [Cu(LH(2))X(2)](n) (X = Cl, Br), K-2[NiL(2)].2H(2)O and K-2[CuL(2)].H2O, where LH(2) = malonamide, wer e isolated. The complexes were characterized by elemental analyses, X- ray powder patterns, magnetic susceptibilities and spectroscopic (vari able-temperature Fe-57-Mossbauer, e.s.r., u.v.-vis., i.r., far-i.r., R aman) studies. Monomeric trans pseudo-octahedral stereochemistries for the neutral 1:2 complexes and square planar structures of D-2h symmet ry for the two ionic complexes are assigned in the solid state. Dimeri c or polymeric five-coordinate structures are proposed for the 1:1 cop per(II) compounds. LH(2) and L(2-) behave as bidentate chelating ligan ds binding through oxygen and deprotonated nitrogen atoms, respectivel y. A detailed comparison of the studied complexes with the correspondi ng oxamide complexes is also presented.