A(2)TiF(5)center dot nH(2)O (A=K, Rb, or Cs; n=0 or 1): Synthesis, structure, characterization, and calculations of three new uni-dimensional titanium fluorides

Abstract

Three new uni-dimensional alkali metal titanium fluoride materials, A(2)TiF(5)center dot nH(2)O (A = K, Rb, or Cs; n=0 or 1) have been synthesized by hydrothermal reactions. The structures of A(2)TiF(5)center dot nH(2)O have been determined by single-crystal X-ray diffraction. The Ti4+ cations have been reduced to Ti3+ during the synthesis reactions. All three A(2)TiF(5)center dot nH(2)O materials contain novel 1-D chain structures that are composed of the slightly distorted Ti3+F6 corner-sharing octahedra attributable to the Jahn-Teller distortion. The coordination environment of the alkali metal cations plays an important role to determine the degree of turning in the chain structures. Complete structural analyses, Infrared and UV-vis diffuse reflectance spectra, and thermal analyses are presented, as are electronic structure calculations. (C) 2011 Elsevier Inc. All rights reserved.