SYNTHESIS, CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES OF BIS(3-AMINO-2-CHLOROPYRIDINE)DIBROMIDOCOPPER(II)
The synthesis, X-ray crystal structure, and variable temperature magnetic properties of [(3-NH2-2-Clpy)2CuBr2] (3-NH2-2-Clpy = 3-chloro-2-aminopyridine) (1) are presented. The compound was characterized using combustion analysis, X-ray powder diffraction, single crystal X-ray diffraction, and temperature-dependent magnetic susceptibility measurements. Compound 1 crystallizes in the monoclinic space group P21/n. Inversion related molecules form a dimeric unit via short Cu…Br contacts. The dimers are linked into a step-like chain via short Br…Br contacts. Surprisingly, magnetic susceptibility measurements (1.8-325 K), which indicate weak antiferromagnetic interactions, are best fit by a uniform chain model suggesting that the exchange within and between dimers is nearly identical. Fitting the data with the S = ½ uniform chain model gave J = -3.38(2) K with C = 0.407(1).