One-dimensional inorganic arrangement in the bismuth oxalate hydroxide Bi(C 2O 4)OH

Abstract

Single crystals of Bi(C 2O 4)OH were obtained by the slow diffusion of Bi 3+ cations through silica gel impregnated with oxalic acid. The structure was solved in the Pnma space group with a=6.0853(2) Å, b=11.4479(3) Å, c=5.9722(2) Å, leading to R=0.0188 and w R=0.0190 from 513 unique reflections. The bismuth coordination polyhedron is a BiO 6E pentagonal bipyramid with the lone pair E sitting at an axial vertex. The opposite axial vertex is occupied by a hydroxyl oxygen atom, which is also an equatorial corner of a neighboring BiO 6E bipyramid. The sharing of the hydroxyl oxygen atoms build ∞ 1 [ BiO 5 E ] zig-zag chains running down the [100] direction. These chains are aligned in a sheet parallel to the (010) plane and are further connected through oxalate ions to form a three-dimensional arrangement. On heating, Bi(C 2O 4)OH decomposes to the meta-stable quadratic β-Bi 2O 3 phase.