Solvent effect on condensation of pyramidal [AsSe3]3–: solvothermal syntheses of new selenidoarsenates containing transition metal(II) complexes with 1,10-phenanthroline
摘要:
The reactions As2O3, Se and 1,10-phenanthroline (phen) with NiCl2 and ZnCl2 in water at 140 degrees C for 5 days afforded selenidoarsenates [Ni(phen)(3)](2)[As8Se14] (1) and [Zn(phen)3](2)[As8Se14] (2), respectively. The reactions with CoCl2 and NiCl2 in CH3OH aqueous solution produced polyselenidoarsenates [Co(phen)(3)][As2Se6] (3) and [Ni(phen)3][As2Se6] (4). All transition metal ions are octahedrally coordinated by six nitrogen atoms and all arsenics are trigonal pyramidally coordinated by three seleniums. In 1 and 2, eight [AsSe3](3-) trigonal pyramids joined via edge-sharing to form [As8Se14](4-) with condensation grade of 0.571. [As8Se14](4-) contains two As3Se3 and one As6Se6 heterocycles. The formations of the selenidoarsenate anion [As8Se14](4-) in 1 and 2 and polyselenidoarsenate [As2Se6](2-) in 3 and 4 show solvent effect on condensation of trigonal bipyramidal [AsSe3](3-) units under solvothermal conditions.