Synthesis, spectral, thermal, and structural studies of copper(II)-squarate coordination polymer with 2-hydroxyethylpyridine, {[Cu(mu-sq)(etpy)_2] centre dot H_2O}_n

摘要

Polynuclear Cu(II)-squarate complex with 2-hydroxyethylpyridine, {[Cu(mu-sq)(etpy)_2] centre dot H_2O}_n has been prepared and characterized by elemental analysis, magnetic susceptibility, thermal analysis, IR, and UV-Vis spectroscopic studies (H_2sq = squaric acid and etpy = 2-hydroxyethylpyridine). The structure of the complex was determined by single crystal X-ray diffraction. Density functional theory (DFT) and Hartree-Fock (HF) calculations were performed using the GAUSSIAN 03 program. The complex crystallizes in the monoclinic system, space group P2_1/c. The structure contains chains of squarato-O~1,O~3-bridged polynuclear copper(II) units held together by intermolecular hydrogen bonds, weak n-n and van der Waals interactions. The distorted octahedral geometry of Cu(II) is completed by two neutral bidentate etpy ligands through the nitrogen of pyridine and hydroxyl O atom. Thermal decomposition of the complex is studied from 30 to 500 deg C in a static air atmosphere.