Acta Crystallographica Section C

Crystal Structure Communications

Volume 58, Part 5 (May 2002)

Acta Cryst. (2002). C58, i55-i60 [doi:10.1107/S0108270102005176]

Copper(II) hypophosphite: the - and -forms at 270 and 100 K, and the -form at 270 K

D. Yu. Naumov, M. I. Naumova, N. V. Kuratieva, E. V. Boldyreva and J. A. K. Howard

Abstract: Copper(II) hypophosphite has been shown to exist as several polymorphs. The crystal structures of monoclinic [alpha] -, orthorhombic [beta] - and orthorhombic [bold gamma] -Cu(H₂PO₂)₂ have been determined at different temperatures. The geometry of the hypophosphite anion in all three polymorphs is very close to the idealized one, with point symmetry mm2. Despite having different space groups, the structures of the [alpha] - and [beta] -polymorphs are very similar. The polymeric layers formed by the Cu atoms and the hypophosphite ions, which are identical in the [alpha] - and [beta] -polymorphs, stack in the third dimension in different ways. Each hypophosphite anion is coordinated to three Cu atoms. On cooling, a minimum amount of contraction was observed in the direction normal to the layers. The structure of the polymeric layers in the [bold gamma] -polymorph is quite different. There are two symmetry-independent hypophosphite anions; the first is coordinated to two Cu atoms, while the second is coordinated to four Cu atoms. In all three polymorphs, the Cu atoms are coordinated by six O atoms of six hypophosphite anions, forming tetragonal bipyramids; in the [alpha] - and [beta] -polymorphs, there are four short and two long Cu-O distances, while in the [bold gamma] -polymorph, there are four long and two short Cu-O distances.

Formula: [alpha] -, [beta] - and [bold gamma] -Cu(H₂PO₂)₂

Online 19 April 2002


	Structure factor file (CIF format) (31.3 kbytes) Contains datablock alpha270

	Structure factor file (CIF format) (30.9 kbytes) Contains datablock alpha100

	Structure factor file (CIF format) (31.9 kbytes) Contains datablock beta270

	Structure factor file (CIF format) (31.7 kbytes) Contains datablock beta100

	Structure factor file (CIF format) (20.8 kbytes) Contains datablock gamma270

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