STRUCTURE AND MAGNETIC-PROPERTIES OF A TRINUCLEAR COPPER(II)-CYCLAM DERIVATIVE ENTER-DOT-VERTICAL-BAR(CH2CL2)2(H2O)4-VERTICAL-BAR

The X-ray structure of the copper derivative \Cu3(C10H24N4)3Cl2\C14.\C H2Cl2)(H2O)4\ is reported. This complex cyrstallizes in the space grou p Pnnm, with unit cell parameters of a = 13.708(4), b = 20.116(6), c = 10.499(3) angstrom, V = 2895.1 angstrom3 and Z = 2. Full-matrix least -squares refinements led to the values of R(F) = 0.045 and Rw(F) = 0.0 66. The structure contains the centrosymmetric, trinuclear copper cati on \Cu3(C10H24N4)3Cl2\4+ in which two chloride ions bridge three coppe r-cyclam units. The coordination polyhedron of the central copper atom is an elongated octahedron whereas that of the outer copper centers i s a square pyramid. The bulk magnetic and EPR properties of this deriv ative show that the coupling of the copper spins is very weak, the cou pling constants lying between 10(-1) and 10(-3) cm-1.