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

Two new coordination polymers, {[Cd(Hmph)(Itmb)] ∙ H₂O}_n (I) and [Zn(Hmph)(Bpt)₂]_n (II) (H₂Hmph = 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 π–π interactions. Complex II displays a zigzag Zn-carboxylate chain structure, which is further extended to the final 3D supramolecular structure by hydrogen-bonding and π–π interactions. TGA experiments indicate that complex I and II have high thermal stabilities because they can maintain framework integrity until 275 and 315°C, respectively. And in comparison, with the free ligands, the fluorescent properties of both CPs show significant blue-shift. [ABSTRACT FROM AUTHOR]