Synthesis, structure and luminescence property of two lanthanum phosphite hydrates: La-2(H2O)(x)(HPO3)(3) (x=1,2)

摘要

Two new lanthanum phosphite hydrates, La-2(H2O)(HPO3)(3) (1) and La-2(H2O)(2)(HPO3)(3) (2), were synthesized by a hydrothermal method. Their crystal structures were determined by X-ray single-crystal method (1, monoclinic, C2/c (No. 15); a = 20.820(5) angstrom, b = 6.717(2) angstrom, c = 14.123(3) angstrom, beta = 101.261(3)degrees, V = 1937.0(8) angstrom(3); Z = 8; 2, triclinic, P-1 (No. 2); a = 8.168(3) angstrom, b = 8.439(2) angstrom, c = 9.337(3) angstrom, alpha = 115.641(3)degrees, beta = 98.655(3)degrees, gamma = 105.124(3)degrees, V = 533.87(1)angstrom(3), Z = 2). Both crystal structures present three-dimensional open-framework structures containing channels, and I adopts intersecting type. In the two structures, the face-sharing dimers of LaOn (n = 8, 9) were observed. Other characterizations by IR and TG-DSC were also described. Furthermore, both the compounds doped with Ce+3 showed intensive broad emission band around 340 nm under UV excitation. (c) 2006 Elsevier Inc. All rights reserved.