Magnetic properties and crystal structure of a 3,5-dimethylpyrazolate-bridged binuclear copper(II) complex

[Cu2L(prz)] (prz = 3,5-dimethylpyrazole and L =1,3-bis(5-bromo-2-hydroxyben zylidene)-propan-2-ol) was synthesized and its crystal structure determined . It crystallizes in the orthorhombic space group Pbca with a=14.160(9), b= 15.109(4), c=21.298(5) Angstrom, V=4557(1) Angstrom (3), Z=8. Two copper(II ) ions are in a square-planar coordination. The metal coordination sphere i s four-coordinate, with a planar N2O2 donor set. The dihedral angle between the two coordination planes is 12.14(7)degrees. The copper(II) centers are separated by 3.365(1) Angstrom and antiferromagnetically coupled (J = -214 .3 cm(-1)), which follows from temperature-dependent magnetic susceptibilit y measurements in the temperature range 4.6 to 3 10 K. The Cu-O-Cu angle is 125.9(1)degrees in the super-exchange pathway. The magnetic moment at 310 K is ca. 1.76 B.M. and 0.13 B.M. at 4.6 K.