Two-dimensional CuII and first PbII coordination polymers based on a flexible 1,4-cyclohexanedicarboxylate ligand displaying different conformations and coordination modes
摘要:
Two novel metal-organic hybrid coordination polymers {[Cu(bpo)(chdc)(H2O)](H2O)(0.5)}(n) (1) and [Pb(chdc)(H2O)](n) (2) have been synthesized under different conditions and structurally characterized by single-crystal X-ray diffraction technique, where H(2)chdc refers to a flexible 1,4-cyclohexanedicarboxylic acid ligand and bpo is 2,5-bis(4-pyridyl)-1,3,4-oxadiazole. Complex 1 has a two-dimensional (2-D) grid-like [11.28 x 13.63 angstrom(2)] framework in which the Cu-II centers are extended via bidentate bridging ligands bpo and e,e-trans-chdc along two directions, exhibiting large porous cavities. Coordination polymer 2 represents the first Pb-II complex of H(2)chdc in which the larger Pb-II centers are connected by e,a-cis-chdc anions to afford a 2-D close-knit structure. (c) 2005 Elsevier B.V. All rights reserved.