Synthesis, characterization and luminescence of Cd(II), Zn(II) complexes with 1,2,3-triazole derivatives and in situ solvothermal decarboxylation of the ligands

The complexes [CdCl(mptc)(H2O)2]n (1), Zn(mptc)(Hmptc)Br (2), {[Zn(mptc)3]2[Zn(H2O)6]·4H2O} (3) and Zn(mpt)2Cl2 (4) (mpt = 5-methyl-1-phenyl-1H-1,2,3-triazole) were prepared by 5-methyl-1-phenyl-1H-1,2,3-triazole-4-carboxylic acid (Hmptc) and Cd2+, Zn2+ respectively in different conditions. We found an interesting phenomenon of in situ decarboxylic reaction in complex 4. The same discovery was also in Zn(ipmt)2Br2 (5) (ipmt = 1-(4-iodophenyl)-5-methyl-1H-1,2,3-triazole), which was obtained by the reaction of 1-(4-iodophenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylic acid (Hipmtc) with Zn2+ under solvothermal condition. And the crystal structures of 1–5 were determined via single-crystal X-ray diffraction. The complexes were characterized by FT-IR, elemental analyses, and solid-state fluorescent emission spectroscopy. Then, the possible mechanism of in situ solvothermal decarboxylation was discussed.