Crystal Chemistry of Gallium(I) in Oxides: Ga(+)-beta"-Alumina and GaZr(2)(PO(4))(3).
Ga(+)-beta"-alumina and GaZr(2)(PO(4))(3) have been prepared by ion exchange techniques from Na(+)-beta"-alumina and AgZr(2)(PO(4))(3), respectively. The structures of both compounds at room temperature are reported along with that for beta"-alumina at 11 K. The coordination chemistries of the Ga(I) cations in the two materials are distinctly different: in Ga(+)-beta"-alumina, the Ga(I) cation displays 3+0-coordination, indicative of a stereochemically active lone pair, with a minimum Ga-O distance of 2.39 Å, but in GaZr(2)(PO(4))(3), Ga(I) is 6-coordinate with a minimum Ga-O distance of 2.80 Å. Both Ga(+)-beta"-alumina and GaZr(2)(PO(4))(3) are stable toward oxidation in air up to approximately 500 degrees C. Crystal data are as follows. Ga(1.6)[(Al(10.7)Li(0.3))O(17)]: rhombohedral, R&thremacr;m, Z = 3; for T = 296 K, a = 5.5951(1) Å and c = 34.3670(8) Å; for T = 11 K, a = 5.5900(1) Å and c = 34.3805(8) Å. GaZr(2)(PO(4))(3): rhombohedral, R&thremacr;c, Z = 6, a = 8.72198(4) Å, c = 23.8820(2) Å.
Wilkinson
A. P.
AP
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400.