Syntheses, Structures, and Properties of Two Cd(II)/Zn(II) Complexes with 1,2,4-triazole Derivatives

Two new coordination polymers, {[Cd(Hmph)(Itmb)] center dot H2O}(n) (I) and [Zn(Hmph)(Bpt)(2)](n) (II) (H(2)Hmph = homophthalic acid, Itmb = 1-(imidazo-1-yl)-4-(1,2,4-triazole-1-ylmethyl)benzene, Bpt = 3,5-bis(4-pyridyl)-1,2,4-triazole) have been prepared and then characterized by single crystal X-ray diffraction (CIF files CCDC nos. 1842595 (I), 1842591 (II)). Complex I shows a 2D layer structure containing Cd-carboxylate chains linked further by itmb coligands, and the ultimate 3D supramolecular structure is stacked through significant pi-pi interactions. Complex II displays a zigzag Zn-carboxylate chain structure, which is further extended to the final 3D supramolecular structure by hydrogen-bonding and pi-pi interactions. TGA experiments indicate that complex I and II have high thermal stabilities because they can maintain framework integrity until 275 and 315 degrees C, respectively. And in comparison, with the free ligands, the fluorescent properties of both CPs show significant blue-shift.