Coordination polymers with a semi-rigid spacer ligand in a mixed system: Roles of benzene-1,3,5-tricarboxylate anions

Abstract

Reactions of divalent metal salts with N,N’-bis(3-pyridyl)terephthalamide (L) and benzene-1,3,5-tricarboxylic acid (1,3,5-H3BTC) under hydro(solvo)thermal conditions afforded five coordination polymers, {[Cd(L)(1,3,5-HBTC)]∙2H2O}n, 1, {[Cu(L)(1,3,5-HBTC)]•H2O}n, 2, {[Zn(L)(1,3,5-HBTC)]∙2H2O}n, 3, {(H2L)0.5[Ni(L)(1,3,5-BTC)(H2O)2]•H2O•}n, 4, and {[Ni1.5(L)1.5(1,3,5-BTC)(CH3OH)2]•3CH3OH}n, 5, which have been structurally characterized by using single-crystal X-ray diffraction. Complexes 1 - 3 adopt the 3,5-connected 2D nets with the {42.67.8}{42.6}-3,5L2 topology, whereas 4 shows a 1D column with the 2,4C6 topology and 5 exhibits a 2D double layer with the hexagonal channels and the 3,4,4L35 topology, indicating the significant effect of the cocrystallized solvent molecules on the structural diversity of 4 and 5. Moreover, complex 5 can be transformed to 4 irreversibly under solvothermal condition, which can be ascribed to the various coordination modes of the benzene-1,3,5-tricarboxylate anions. The thermal properties of complexes 1–5 and the luminescent properties of 1 and 3 are also discussed.