We have developed a water-based synthesis for the preparation of 4-substituted 1,2,4-triazole ligands with highly polar functional groups. This general synthetic approach has allowed us to prepare two sulfonate functionalized 4-substituted 1,2,4-triazole anions (L1−− = 4-(1,2,4-triazol-4-yl)benzenesulfonate; L2−− = 4-(1,2,4-triazol-4-yl)ethanesulfonate). Reaction of these ligands with cadmium(II) salts leads to the formation of two novel two-dimensional coordination networks of formula [Cd(L)Cl]n (1, L1; and 2, L2), which were structurally characterized by X-ray diffraction. In both compounds, the cadmium ions are bridged by chloride ions and the triazole ligands in a bis-bidentate coordination mode using the N1, N2 atoms from the triazole and two oxygen atoms from the –SO3 group. The photoluminescence studies indicate that the ligand photoemission is retained in these networks.
Aqueous synthesis of sulfonate-functionalized 1,2,4-triazole ligands and their 2D Cd2+ coordination networks: crystal structure and photoluminescent properties
Dalton Trans. 2013, 42, 6374-6380.