Synthesis and crystal structure of a new neodymium(III) selenate-selenite: Nd_2(SeO_4)(SeO_3)_2(H_2O)_2 Mei-Ling Feng

摘要

The title new neodymium(III) selenate-selenite was obtained by hydrothermal reactions of neodymium(III) oxide, H_2SeO_4 and 1,10-phenanthroline at 140 deg C. Its structure was established by single-crystal X-ray diffraction. The title compound crystallizes in the mono-clinic space group C2/c with cell parameters of a = 12.258(2) A, b = 7.1024(15) A, c = 13.391(3) A, beta = 104.250(2) deg. The structure of Nd_2(SeO_4)(SeO_3)_2(H_2O)_2 is isomorphous with that of Er_2(SeO_4)(SeO_3)_2(H_2O)_2, which was refined in the monoclinic space group C2 with the disordered selenate group. It features an ordered 3D network with channels along b-axis. The selenate or selenite groups alone can form a 2D layer with the Nd(III) ions. IR spectrum, TGA and luminescent studies have also been performed.