C–H⋯Cl relevant discrepancy on structure, magnetic and electronic conductivity of two mixed-valence CuICuII coordination polymers

Abstract: Two mixed-valence CuICuII coordination polymers [CuICuII(qdiol)ClL] n (qdiol2−=2,3-dioxyquinoxalinate, L=2,2′-bipyridine, 1; L=1,10-phenanthroline, 2) were obtained in basic ethanolic solution of CuCl2, 1,4-dihydro-2,3-quinoxalinedione and L under the solvothermal condition. 1 and 2 are similar in composition, but differ remarkably in structure. The coordination modes of CuII, qdiol2− and L are identical in both complexes. But the CuI ions are two- and three-coordinated, and the Cl− ions are terminal and bridging, in 1 and 2, respectively, which are relevant to the significantly different C–H⋯Cl hydrogen bonding pattern of bpy and phen. The temperature variable magnetic susceptibilities show that 1 is paramagnetic and 2 is weakly antiferromagnetic. The complex impedance spectroscopic studies indicate that both 1 and 2 are semiconductors and 2 is more conducting. [Copyright &y& Elsevier]