Coordination polymers from main group ring compounds

Abstract

4,7-dicyano-2,1,3-benzothiadiazole, L1, and diethyl-4,7-dicarboxylato-2,1,3 benzothiadiazole, L2, form coordination polymers with silver(I) salts of weakly-coordinating anions. Synthesis was achieved by the slow diffusion of benzene solutions of the silver salts into dichloromethane solutions of L1 or L2. Slow growth of crystals occurred with partial evaporation of the solvent, leading to a number of different crystalline coordination polymers. For L1, both the nitrile and ring N atoms can coordinate with great variability of structural motifs, whereas for L2 a chelating geometry is always found in which each Ag+ is coordinated by two N and two carbonyl O from different ligands. The resulting coordination polymers form layer structures that tend to fill with solvent benzene molecules in a stoichiometric fashion; the benzenes are found to π-coordinate to silver.