Effect of Anions on the Framework Formation of Novel Ag^I Coordination Polymers with Angular Bridging Ligands

Coordination networks based on the organic ligand 2,5-bis(4-pyridyl)-1,3,4-thiadiazole (L) or 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L) and various inorganic silver(I) salts were prepared and characterized by single-crystal X-ray analysis. Reaction of AgPF6 or AgClO4·H2O and L1 in CH3OH/CHCl3 medium afforded a unique two-dimensional coordination polymer {[Ag(L1)](PF6)}∞ (1) or {[Ag(L1)](ClO4)}∞ (2) with (2/4,3) topology. However, with the replacement of AgPF6 or AgClO4·H2O with AgNO3 in the above reaction, an interesting three-dimensional coordination architecture {[Ag4(L1)4(NO3)2](NO3)2}∞ (3) constructed through weak interactions between nitrate ions and two different one-dimensional motifs was obtained. Furthermore, two one-dimensional coordination chains {[AgL1](CF3SO3)}∞ (4) and {[Ag(L2)] (CF3SO3)}∞ (5), with different structural geometries, were obtained by the reactions of AgCF3SO3 with L1 and L2, respectively. The structural diversities of these complexes demonstrate that counteranions play essential roles in the construction of such supramolecular frameworks.