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The crystal structure of chalcoalumite: mechanisms of Jahn-Teller-driven distortion in [6]Cu2+-containing oxysalts

Published online by Cambridge University Press:  05 July 2018

F. C. Hawthorne  and
M. A. Cooper
F. C. Hawthorne*
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
M. A. Cooper
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
*
* E-mail: frank_hawthorne@umanitoba.ca
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Abstract

The crystal structure of chalcoalumite, ideally Cu2+Al4(SO4)(OH)12(H2O)3, monoclinic, P21/n, Z = 4:a 10.228(3), b 8.929(3), c 17.098(6) Å, β 95.800(11)°, V 1553.6(1.5) Å3, has been refined to R1 = 3.08% for 4,022 unique observed (4σ) reflections collected on a Bruker D8 three-circle diffractometer equipped with a rotating-anode generator, multilayer optics and an APEX-II CCD detector. In the structure of chalcoalumite, there is one S site, tetrahedrally coordinated by four O anions, with <S–O> = 1.472 Å. There are four Al sites with site-scattering values in accord with occupancy by Al and <Al–O> distances of 1.898–1.919 Å. There is one Cu site occupied by Cu2+ and coordinated by six anions in the [4 + 2] arrangement typical for octahedrally coordinated Cu2+. The short <Cu–O> distance of 2.086 Å is in accord with the low degree of bond-length distortion of the Cu octahedron. There are 19 anion sites: 4 sites are occupied by O atoms that are bonded to the S cation, 12 sites are occupied by (OH) groups that bond to all octahedrally coordinated cations, and 3 sites are occupied by (H2O) groups that are held in the structure solely by hydrogen bonding. The structure of chalcoalumite consists of interrupted sheets of edge-sharing Al and Cu octahedra of the form [Cu2+Al4(OH)12]2+ that intercalate layers of (SO4) tetrahedra and (H2O) groups. Chalcoalumite is a member of the nickelalumite group.

Cu2+ϕ6(ϕ = O2–, (OH)–, (H2O)0) octahedra show a wide range of bond-length distortion away from the holosymmetric arrangement, driven by spontaneous symmetry-breaking of the degenerate electronic ground-state in holosymmetric octahedral coordination. Here, we examine the structural mechanisms that allow large octahedron distortions of this type. There are two mechanisms: (1) coupling of (usually parallel) octahedron distortions to a vibrational phonon, inducing a (often ferroelastic) phase transition in M2+-Cu2+ solid-solutions; (2) cooperative orientational disorder, where bond topology (polyhedron linkage) allows large differences in bond lengths within polyhedra to accord with the valence-sum rule of bond-valence theory.

Keywords

chalcoalumitecrystal structuresulfatenickelalumite group
Type
Research Article
Information
Mineralogical Magazine , Volume 77 , Issue 7 , October 2013 , pp. 2901 - 2912
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Agakhanov, A.A., Karpenko, V.Y., Pautov, L.A., Uvarova, Y.A., Sokolova, E., Hawthorne, F.C. and Bekenova, G.K. (2005) Kyrgyzstanite, ZnAl4(SO4) (OH)12(H2O)3 – a new mineral from the Kara-Tangi, Kyrgyzstan. New Data on Minerals, 40, 23–28.Google Scholar
Brown, I.D. (2002) The Chemical Bond in Inorganic Chemistry. The Bond Valence Model. International Union of Crystallography Monographs on Crystallography, 12. Oxford University Press, USA.Google Scholar
Brown, I.D. and Altermatt, D., (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244–247.CrossRefGoogle Scholar
Bruker Analytical X-ray Systems (1997) SHELXTL Reference Manual 5.1., Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Burns, P.C. and Hawthorne, F.C. (1996) Static and dynamic Jahn-Teller effects in Cu 2+ -oxysalt minerals. The Canadian Mineralogist, 34, 1089–1105.Google Scholar
Burns, P.C., Hawthorne, F.C. and Hofmeister, A.M. (1996) A structural phase transition in K(Mg1–xCux)F3 perovskite. Physics and Chemistry of Minerals, 23, 141–150.CrossRefGoogle Scholar
Cooper, M.A. and Hawthorne, F.C. (1996) The crystal structure of shigaite, [AlMn+(OH)6]3(SO4)2Na (H2O)6{H2O}6, a hydrotalcite-group mineral. The Canadian Mineralogist, 34, 91–97.Google Scholar
Eby, R.K. and Hawthorne, F.C. (1993) Structural relations in copper oxysalt minerals. I. Structural hierarchy. Acta Crystallographica, B49, 28–56.CrossRefGoogle Scholar
Frost, R.L., Reddy, B.J. and Keeffe, E.C. (2010) Structure of selected basic copper(II) sulphate minerals based on spectroscopy. Implications for hydrogen bonding. Journal of Molecular Structure, 977, 90–99.CrossRefGoogle Scholar
Hawthorne, F.C. and Schindler, M., (2000) Topological enumeration of decorated [Cu2+j2]N sheets in hydroxy-hydrated copper-oxysalt minerals. The Canadian Mineralogist, 38, 751–761.CrossRefGoogle Scholar
Hawthorne, F.C., Krivovichev, S.V. and Burns, P.C. (2000) The crystal chemistry of sulfate minerals. Pp. 1–112. in: Sulfate Minerals: Crystallography, Geochemistry, and Environmental Significance (Alpers, C.N., Jambor, J.L. and Nordstrom, D.K., editors). Reviews in Mineralogy and Geochemistry, 40, Mineralogical Society of America and Geochemical Society, Washington, D.C.Google Scholar
Jahn, H.A. and Teller, E., (1937) Stability of polyatomic molecules in degenerate electronic states. I. Orbital degeneracy. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, 161(905), 220–235.Google Scholar
Karpenko, V.V., Pautov L.A., Sokolova, E., Hawthorne, F.C., Agakhanov, A.A., Dikaya, T.V. and Bekenova, G.K. (2004a) Ankinovichite, nickel analogue of alvanite, a new mineral from Kurunsak (Kazakhstan) and Kara-Chagyr (Kirgizia). Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva, 133, N2, 59–70.Google Scholar
Karpenko, V.V., Agakhanov, A.A., Pautov, L.A., Dikaya, T.V. and Bekenova, G.K. (2004b) New occurrence of nickelalumite on Kara-Chagyr, South Kirgizia. New Data on Minerals, 39, 32–39.Google Scholar
Krivovichev, S.V., Yakovenchuk, V.N., Zhitova, E.S., Zolotarov, A.A., Pakhomosky, Y.A. and Ivanyuk, G.Yu. (2010) Crystal chemistry of natural layered double hydroxides. 1. Quintinite-2H-3c from the Kovdor alkaline massif, Kola peninsula, Russia. Mineralogical Magazine, 74, 821–832.CrossRefGoogle Scholar
Larsen, E.S. and Vassar, H.E. (1925) Chalcoalumite, a new mineral from Bisbee, Arizona. American Mineralogist, 10, 79–83.Google Scholar
Martini, J.E.J. (1980) Mbobomkulite, hydrombobomkulite, and nickelalumite, new minerals from Mbobo Mkulu cave, eastern Transvaal. Annals of the Geological Survey of South Africa, 14, 1–10.Google Scholar
Mills, S.J., Christy, A.G., Genin, J.-M.R, Kameda, T., and Colombo, F., (2012) Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides. Mineralogical Magazine, 76, 1289–1336.CrossRefGoogle Scholar
Pertlik, F. and Dunn, P.J. (1990) Crystal structure of alvanite, (Zn,Ni)Al4(VO3)2(OH)12·2H2O, the first example of an unbranched zweier-single chain vanadate in nature. Neues Jahrbuch für Mineralogie, Monatshefte, 9, 385–392.Google Scholar
Rubins, R.S. and Drumheller, J.E. (1987) The temperature dependence of the EPR spectrum of Cu2+ in ZnTiF6.6H2O between 4 and 160 K. Journal of Chemical Physics, 86, 6660–6664.CrossRefGoogle Scholar
Rubins, R.S., Tello, L.N., De, D.K. and Black, T.D. (1984) Jahn-Teller EPR spectra of Cu2+ in MgSiF6.6H2O between 4 and 160 K. Journal of Chemical Physics, 81, 4230–4233.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.CrossRefGoogle Scholar
Uvarova, Y.A., Sokolova, E., Hawthorne, F.C., Karpenko, V., Agakhanov, A.A. and Pautov, L.A. (2005) The crystal chemistry of the “nickelalumite”- group minerals. The Canadian Mineralogist, 43, 1511–1519.CrossRefGoogle Scholar
Williams, S. and Khin, B.S. (1971) Chalcoalumite from Bisbee, Arizona. Mineralogical Record, 2, 126–127.Google Scholar
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