Synthesis and structure of Cs3Ti3As5O20

Abstract

A new ternary titanium arsenate, Cs₃Ti₃As₅O₂₀, has been synthesized and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Pbcm(no. 57) with a= 6.5084(9), b= 19.167(1), c= 15.377(1)Å, Z= 4 and R= 0.0259. The structure consists of tunnels where the caesium cations are located. The framework is formed by corner-sharing monomeric TiO₆ octahedra, dimeric Ti₂O₁₁ units consisting of two corner-sharing TiO₆ octahedra, AsO₄ tetrahedra, and As₂O₇ groups. The structural formula is Cs₃Ti(Ti₂O)(AsO₄)₃(As₂O₇). The structure is compared with that of α-CsTi₃P₅O₁₉.