RbIn(OH)PO4: an indium(III) phosphate containing spirals of corner-sharing InO6 octahedra

Abstract

An indium(III) phosphate, RbIn(OH)PO₄, was synthesized using a high temperature, high pressure hydrothermal method and characterized by single-crystal X-ray diffraction. The compound crystallizes in the tetragonal space group P4₃2₁2 (no. 96) with a= 9.400(2), c= 11.179(4)Å, U= 987.8(4)ų and Z= 8. The structure consists of spirals of cis corner-sharing InO₆ octahedra running parallel to the c axis. The hydroxyl oxygen is the bridging atom. The In–O–In bonds are nearly equidistant. The composition was further defined by thermogravimetric and infrared spectroscopy measurements. Second harmonics were generated in powdered RbIn(OH)PO₄ to confirm the absence of a centre of symmetry in the structure.