SYNTHESIS, CRYSTAL-STRUCTURE AND MAGNETIC-PROPERTIES OF AN IMIDAZOLATE-BRIDGED DINUCLEAR NICKEL(II) COMPLEX - MU-(IM)-[(232-TET)NI](2)(CLO4)(3)

An imidazolate bridged dinuclear nickel(II) complex, mu-(Im)-[(232-tet )Ni](2)(ClO4)(3), where 232-tet = N,N'-bis(2-aminoethyl)-1,3-propanedi amine, Im = imidazolate anion, has been synthesized and its crystal st ructure determined. Crystals are monoclinic, space group C2, with a = 11.982(4), b = 12.320(2), c = 11.711(4) Angstrom, beta = 110.97(2)degr ees and Z = 2. Least-squares refinement of the structure leads to R an d R-w, factors of 0.036 and 0.044, respectively. The structure consist s of discrete dinuclear cations, mu(Im)-[(232-tet)Ni](2)(3+), with the intramolecular nickel(II)-nickel(II) separation being 6.190(3) Angstr om, and three perchlorate counter anions. Each nickel(II) atom is five -coordinated in a square pyramid with the four N atoms of the 232-tet ligand in the basal positions and one N atom of the Im anion in the ap ical position. The Ni-N(Im) and average Ni-N (232-tet) bondlengths are 2.049(4) and 2.086(4) Angstrom, respectively. Magnetic susceptibility measurements in the temperature range 1.5 to 300K show that the two n ickel(II) atoms of the dinuclear unit are antiferromagnetically couple d with J = -12.5 cm(-1), g = 2.19, T-N being ca 25K.