Synthesis, crystal structure, EPR spectra of doped VO 2+ and Cu 2+ ions in [Zn(ethylisonicotinate) 2(H 2O) 4]·(sac) 2 single crystal

Abstract

The tetraaquabis(ethylisonicotinate)zinc(II) disaccharinate, [Zn(ein) 2(H 2O) 4]·(sac) 2 (ZENS) (ein: ethylisonicotinate and sac: saccharinate) complex has been synthesized and its crystal structure has been determined by X-ray diffraction analysis. The magnetic environments of VO 2+ and Cu 2+ doped Zn(II) complex have been identified by electron paramagnetic resonance (EPR) technique. The title complex crystallizes in monoclinic system with space group P2 1/ c, Z = 4. The octahedral Zn(II) ion, rides on a crystallographic centre of symmetry, is coordinated by two monodentate ein ligands through the ring nitrogen and four aqua ligands to form discrete [Zn(ein) 2(H 2O) 4] unit, which captures two saccharinate ions in up and down positions, each through intermolecular hydrogen bonds. Cu 2+ and VO 2+ doped ZENS single crystals have been studied at room temperature in three mutually perpendicular planes. The calculated results of the Cu 2+ and VO 2+ doped in ZENS indicate that Cu 2+ and VO 2+ ion substitute with the Zn 2+ ion in the host lattice. The angular variations of the EPR spectra have shown that two different Cu 2+ and VO 2+ complexes are located in different chemical environments, and each environment contains two magnetically inequvalent Cu 2+and VO 2+sites in distinct orientations occupying substitutional positions in the lattice and show very high angular dependence. The ground state wave functions of the unpaired electron of Cu 2+ ion have been constructed and type of the distortion has, then, been determined.