cg025551a_si_001.cif (15.71 kB)

{[Cd(bpo)(SCN)2]·CH3CN}n:  A Novel Three-Dimensional (3D) Noninterpenetrated Channel-Like Open Framework with Porous Properties

Download (15.71 kB)
posted on 18.09.2002, 00:00 by Miao Du, Shen-Tan Chen, Xian-He Bu
Reaction of CdCl2·0.5H2O with 2,5-bis(4-pyridyl)-1,3,4-oxodiazole (bpo) and NH4SCN in a 1:1:2 molar ratio under CH3CN−H2O medium afforded a novel neutral three-dimensional (3D) coordination polymer {[Cd(bpo)(SCN)2]·CH3CN}n (1) [monoclinic, space group P21/c, a = 7.680(2) Å, b = 10.029(3) Å, c = 25.786(7) Å, β = 93.779(5)°, Z = 4]. The crystal structure reveals that 1 has a 3D noninterpenetrating open framework with guest CH3CN molecules in the cavities, in which the CdII centers (with CdN4S2 octahedral geometry) are bridged by the bpo molecules and SCN- groups. It is interesting that the two-dimensional sheet in this 3D network consists of 16-membered [Cd4(μ-SCN-N,S)4] rings, and the bpo molecules extend these layers to a 3D structure, which is further stabilized by C−H···N hydrogen-bonding and strong ππ-stacking interactions. Thermogravimetric analysis and X-ray powder diffraction technique measurements illustrate that the framework of 1 is retained upon removal of the uncoordinated guest acetonitrile molecules, indicating that 1 might be used to generate microporous material.