Two Copper(II) coordination polymers constructed from 3,3-dimethylglutarate and citrate ligands

Abstract

Two new Cu(II) coordination polymers, formulated as [Cu(μ4-dmg)(DMF)]n (1) and [Cu4(μ4-cit)2(H2O)8]n (2) (H2dmg = 3,3-dimethylglutaric acid and H4cit = citric acid) were successfully synthesized by using H2dmg and H4cit ligands under solvothermal conditions and characterized by single crystal X-ray diffraction, elemental analyses, IR spectroscopy and powder X-ray diffraction (PXRD). Single crystal X-ray analyses indicate that compound 1 features a two-dimensional (2D) structure with a uninodal 4-connected sql/Shubnikov tetragonal plane net, whereas 2 displays a three-dimensional frameworks (3D) with a pcu topology. Cu1 ion in 1 is connected by four bridging carboxylates to produce a paddlewheel-shaped {Cu2(CO2)4} SBU, and each Cu(II) ion is also coordinated to a DMF ligand at the axial site of the paddlewheel SBU. In 2, citrate anion acts as a heptadentate ligand and three independent Cu(II) ions are bridged by two carboxyl and one hydroxy groups to form the trinuclear {Cu3} core. Moreover, thermal and optical band gap properties of the compounds were determined in detailed.