Crystal structures and Raman spectra of Cu(OH)F and Cu₃(OH)₂F₄

Author(s)

Gerald Giester, Eugen Libowitzky

Abstract

Crystals of Cu(OH)F and Cu3(OH)2F4 have been synthesized at low-hydrothermal conditions in sizes up to 0.3 mm. The structures were solved from CCD X-ray single-crystal data and refined to R = 0.033 and 0.019, respectively.

Cu(OH)F: space group P21/a, Z = 4, a = 5.301(1) Å, b = 6.376(1) Å, c = 5.074(1) Å, β = 112.90(1)°, and V = 157.98(5) Å3.

Cu3(OH)2F4: space group P21/n, Z = 2, a = 5.501(1) Å, b = 4.766(1) Å, c = 8.462(1) Å, β = 92.28(1)°, and V = 221.68(7) Å3.

In both compounds the copper atoms are 4 + 2 coordinated to their ligands (Jahn-Teller distortion). Cu(OH)F is isotypic to Cu(OH)Cl, forming layers of edge-sharing Cu(OH)3F3 polyhedra, which are interconnected by hydrogen bonds. The structure of Cu3(OH)2F4 is characterized by chains of edge-sharing Cu(OH)2F4 polyhedra running along [1 0 0], which are linked to each other via corners to form a framework. Hydrogen bonds of the type O—H···F occur with O···F distances of 2.619 and 2.697 Å in Cu(OH)Fand Cu3(OH)2F4, respectively. The observed O—H stretching frequencies of 3129 and 3306 cm–1, respectively, in Raman spectra are in excellent agreement with expected values from distance — frequency correlations. Moreover, the pleochroism of the bands corresponds in both compounds to the O—H orientation found in the structure determination.

Organisation(s)

Department of Mineralogy and Crystallography

Journal

Zeitschrift für Kristallographie : international journal for structural, physical, and chemical aspects of crystalline materials

Volume

218

Pages

351-356

No. of pages

6

ISSN

0044-2968

DOI

https://doi.org/10.1524/zkri.218.5.351.20735

Publication date

2003

Peer reviewed

Yes

Austrian Fields of Science 2012

1051 Geology, Mineralogy

Portal url

https://ucrisportal.univie.ac.at/en/publications/583fc17c-b042-4358-a68b-db49e7a62a08