(IUCr) Crystallography Journals Online

Acta Cryst. (2009). E65, i28 [ doi:10.1107/S1600536809009088 ]

A polymorph structure of copper(II) hydrogenphosphite dihydrate

L. Yang, S. Li and Q. Wang

Abstract: The title compound, poly[[diaquacopper(II)]- [mu] ₃-hydrogenphosphito], [Cu(HPO₃)(H₂O)₂]_n, (I), has been prepared by hydrothermal synthesis at 393 K. Its non-centrosymmetric polymorph structure, (II), was known previously and has been redetermined at 193 (2) K [El Bali & Massa (2002). Acta Cryst. E58, i29-i31]. The Cu atoms in (I) and (II) are square-pyramidal coordinated. A distorted octahedral geometry around the Cu atoms is considered by including the strongly elongated apical distances of 2.8716 (15) Å in (I) and 3.000 (1) Å in (II). The CuCu separation of the dimeric unit is 3.1074 (3) Å. The secondary building units (SBU) (the Cu₂O₂ dimer and two HPO₃ units) in (I) are inversion related and form a two-dimensional layered structure, with sheets parallel to the bc plane, whereas in the structure of (II), the chain elements are connected via screw-axis symmetry to form a three-dimensional microporous framework. In both polymorph structures, strong O-HO hydrogen bonds are observed.

Online 19 March 2009