Main content area

Influence of metal ions on the formation of new metal complexes constructed from tetrachlorophthalic acid

Dai, An-Qi, Yan, Qi, Zhong, Jing, Chen, Sheng-Chun, He, Ming-Yang, Chen, Qun
Zeitschrift für Naturforschung 2015 v.70 no.10 pp. 711-718
X-ray diffraction, ambient temperature, anions, cadmium, copper, dimethylformamide, fluorescence, geometry, hydrogen bonding, infrared spectroscopy, ligands, metal ions, nickel, salts, solvents, thermogravimetry
Reaction of 3,4,5,6-tetrachloro-1,2-benzenedicarboxylyic acid (1,2-H₂BDC-Cl₄) with transitional metal salts at room temperature in mixed DMF/H₂O solvent affords three complexes formulated as [Cu(1,2-HBDC-Cl₄)₂(DMF)₂] (1), {[Cd(1,2-HBDC-Cl₄)₂(H₂O)₄]·2DMF} (2), and {[Ni(1,2-BDC-Cl₄)(H₂O)₅]·DMF·H₂O} (3) (DMF = N,N-dimethylformamide). All these complexes have been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray crystallography. In 1, the Cuᴵᴵ ion is four-coordinated with a square-planar geometry formed by two 1,2-HBDC-Cl₄ anions and two DMF ligands; in 2, the Cdᴵᴵ ion takes an octahedral geometry coordinated by two 1,2-HBDC-Cl₄ anions and four aqua ligands; while in 3, the Niᴵᴵ ion is octahedrally coordinated by one 1,2-BDC-Cl₄ dianion and five aqua ligands. Intermolecular O–H···O hydrogen bonds and Cl···Cl (or C–H···Cl) interactions provide a significant contribution to stabilizing the three mononuclear structures in the solid state. The results suggest that structural differences among them are attributed to the influence of transition metal ions. The fluorescence of the complexes and of 1,2-H₂BDC-Cl₄ has been investigated. No significant metal effect has been observed.