Synthesis, Crystal Structure, Spectroscopic, Fluorescent, Thermal Properties and EPR Spectra of Doped Cu2+ Ions in [Cd(sac)2(H2O)2] Single Crystal

Abstract

The crystal structures of the six-coordinate complexes [Cd(sac) <inf>2</inf>(H<inf>2</inf>O)<inf>2</inf>(meim)<inf>2</inf>] (complex 1) formed by reaction of 4-methylimidazole(meim) with [Cd(sac)<inf>2</inf>(H <inf>2</inf>O)<inf>4</inf>]2H<inf>2</inf>O (saccharinate = sac), was synthesized and characterized by elemental analysis, infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy, thermal analysis and X-ray single crystal diffraction. X-ray diffraction analysis revealed that complex 1 crystallized in the monoclinic crystal system with space group P2<inf>1</inf>/c. The Cd(II) center was six-coordinated with four nitrogen atoms from two sac and two 4-meim ligands, two oxygen atoms from two aqua ligands. Spectral and thermal analysis data for complex 1 was in agreement with the crystal structures. In addition complex 1 displayed blue fluorescent emission in the solid state at room temperature. Single crystal EPR spectra at room temperature are resolved and have exhibited that two different Cu2+ complexes were located in different chemical environments which contained two magnetically nonequivalent Cu2+ sites. In low temperature EPR spectra down to 110 °C did show no considerable change. At higher temperatures, however, both thermo gravimetric analyses (TGA) and EPR spectra showed detectable changes around 140 °C; the causes and the mechanisms of changes are discussed. © 2013 Elsevier B.V. All rights reserved.