A group of new selenite-chlorides of strontium and d-metals (Co,Ni): Synthesis, thermal behavior and crystal chemistry

摘要

The new selenite-chlorides with composition Sr-3(SeO3)(2)Cl-2 (I) and Sr2M(SeO3)(2)Cl-2 (M = Co, Ni (II and III)) were obtained. They crystallize in monoclinic system I: space group C2/m, a = 13.203(2)angstrom, b = 5.5355(8)angstrom, c = 6.6170(10)angstrom, beta = 95.89(1)degrees, Z= 2; II Space group P2(1), a = 5.3400(10)angstrom, b = 6.4279(6)angstrom, c=12.322(1)angstrom, beta=92.44(1)degrees, Z=2; III: space group P2(1), a=5.3254(11)angstrom, b = 6.4363(13)angstrom, c = 12.197(2), beta = 92.53(3)degrees, Z = 2. All three compounds are constructed in the same manner. Sr polyhedra form infinite layers, which are interconnected into a 3D framework by means of Sr polyhedra in the case of I or Co and Ni polyhedra in the case of II and III. Se atoms are situated inside the channels of the 3D framework. The topological analysis of ELF for I confirmed that the lone electron pairs of SeO3 groups are located inside these channels. (C) 2008 Elsevier Inc. All rights reserved.