Crystal structure and intercalation properties of gamma-Zr(AsO4)(H2AsO4)x2H(2)O

The crystalline structure of gamma-Zr(AsO4)(H2AsO4) x 2 H2O (gamma-ZrAs) ha s been refined by the Rietveld method. It has a monoclinic P2(1) layered st ructure built up from AsO4 tetrahedra and ZrO6 octahedra stacked along the 001 direction. The cell parameters are: a = 5.5752(6) Angstrom, b = 6.8290( 7) Angstrom, c = 12.110(1) Angstrom, and beta = 103.03(1)degrees. The layer ed nature of gamma-ZrAs is confirmed by the intercalation of n-alkylamines (CH3[CH2](n)NH2; n = 0-5) as well as of cyclic amines (benzylamine, cyclohe xylamine, piperidine, and pyridine). Among the Linear amines, only with met hyl-, ethyl-, and hexylamine is the maximum incorporation attained. With th e cyclic amines, except in the case of pyridine, pure new phases are obtain ed, with the highest degree of intercalation being one mol of amine per mol of gamma-ZrAs.