BINUCLEAR NICKEL-COMPLEXES WITH SINGLE AZIDE BRIDGES - STRUCTURE AND PROPERTIES OF DYLMETHYL)ETHANE-1,2-DIAMINE)(2)(MU-N-3)](CLO4)(3) AND HYL)-1,4,7-TRIAZACYCLONONANE)(2)(MU-N-3)](CLO4)(3)

The mononuclear precursors [Ni(trenpy)(OH2)](ClO4)(2) (1) and [Ni(dmpt acn)(OH2)](ClO4)(2) (2) have been used to prepare the corresponding az ide bridged binuclear Ni(II) complexes [Ni-2(trenpy)(2)(mu-N-3)](ClO4) (3) (3), where trenpy is minoethyl)-N'-(2-pyridylmethyl)ethane-1,2-dia mine, and [Ni-2(dmptacn)(2)(mu-N-3)](ClO4)(3) (4), where dmptacn is 1, 4-bis(2-pyridylmethyl)-1,4,7-triazacyc These complexes have been chara cterized using various physicochemical techniques. Single-crystal X-ra y diffraction studies of [Ni-2(trenpy)2(mu-N-3)](ClO4)3 have shown tha t the compound crystallizes in the monoclinic space group, C2/c (No. 1 5), with a = 29.094(22) Angstrom, b 8.292(6) Angstrom, c = 15.127(12) Angstrom, beta = 92.93(6)degrees, and Z = 4. Least-squares refinement gave final R and R(W), values of 0.060 and 0.049, respectively, for 14 01 observed reflections. The complex cation consists of two Ni-(II) ce nters in distorted octahedral environment held together by a single az ide bridge. The binuclear unit is centrosymmetric with a Ni-N(azide) b ond distance of 2.133(7) Angstrom, Ni-N-N angle of 131.6(5)degrees, an d torsion angle of 0 degrees, The Ni-N(amine) bond lengths (2.07-2.11 Angstrom) are typical of Ni(II) amine complexes. The temperature depen dence of the magnetic susceptibility for both complexes is typical of antiferromagnetically coupled binuclear Ni(II) complexes. Using the sp in Hamiltonian, -2J (S) over cap(1).(S) over cap 2, J values of -26.8 and -42.5 cm(-1) were determined for 3 and 4, respectively.