Diverse Structures and Physicochemical Properties of Four Zinc–Tripyridyltriazole Coordination Polymers Regulated by Counter-Ions

Abstract

Four distinct ZnII coordination polymers [Zn(L5)Cl2]n (1), [Zn(L5)I2]n (2), {[Zn(L5)(N3)2](H2O)2}n (3), and {[Zn(L5)2(H2O)](ClO4)2(CH3OH)}n (4) were prepared by assembling a multidentate tripyridyltriazole building block 3-(2-pyridyl)-4-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (L5) with different ZnII salts. Compounds 1, 2 and 4 display distinguishing 1D chain-like coordination patterns whereas 3 reveals a 2D uninodal four-connected network, which can be well regulated by different counter-ions. Further, the building tecton L5 exhibits multiple conformations in these structures. The structural diversity reveals that the synergistic modulation of counter-ions and the adaptable conformations of the organic linker play a critical role in the structural construction. Solid-state properties including thermal stability and fluorescence were investigated as well.