Syntheses and structures of mononuclear and binuclear transition metal complexes (Cu, Zn, Ni) with (salicylideneglycine and imidazole)

Abstract

Four transition metal (Cu(II), Zn(II) and Ni(II)) complexes with a Schiff-base ligand (salicylideneglycine) have been synthesized. All complexes have been characterized by elemental analysis, IR spectra and UV-vis spectroscopy. Single-crystal analyses were performed with (C₉H₇NO₃)Cu(C₃H₄N₂) (1), (C₉H₇NO₃)Zn(C₃H₄N₂)₂ (2), (C₉H₇NO₃)₂Ni₂(C₃H₄N₂)₄ (3) and (C₉H₇NO₃)Ni(C₃H₄N₂)₂(C₄H₅N₂O) · CH₃OH · 0.5H₂O (4) and fluorescence spectra and thermogravimetric analyses were also carried out. Structural analyses show that 1, 2 and 4 have similar coordinated modes with the tridentate amino-Schiff-base ligand, but differ from the binuclear nickel complex 3. The tridentate amino-Schiff-base ligand contains aliphatic nitrogen, phenoxy, and carboxylic oxygen as three donor atoms. In addition, inter- and intra-molecular hydrogen bonds are also discussed.

Keywords:

• Transition metal complexes
• Salicylideneglycine ligand
• Supramolecular assembly
• Hydrogen bond
• Crystal structures

Acknowledgements

We wish to express our sincere thanks to the National Natural Science Foundation of China (No. 20571036), the Education Foundation of Liaoning Province (No. 05L212), the SRF for ROCS, and SEM for financial assistance.