Synthesis and crystal structure of Cd2SbBr2

New cadmium bromoantimonide Cd2SbBr2 is prepared by the standard tube metho d. Its crystal structure is solved by the direct methods and refined to R = 0.0328 for 1374 independent reflections and 69 variable parameters. The co mpound crystallizes in the monoclinic space group P2(1): a = 8.244(1), b = 9.920(1), c = 8.492(1) Angstrom, beta = 116.80(1)degrees. The presence of b inuclear Sb-2(4-) anions (Sb-Sb = 2.78 Angstrom) with an octahedral environ ment comprised of six cadmium atoms is the most interesting feature of the structure. The Sb2Cd6 octahedra share equatorial vertices to form layers. T he layer alternation motif is close to that reported for cadmium and mercur y chloroarsenides.