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Synchrotron radiation diffraction study of the mineral moolooite, and synthetic copper oxalates

Published online by Cambridge University Press:  07 March 2019

B. H. O'Connor*
Affiliation:
Department of Physics and Astronomy, Curtin University, Kent St, Bentley, Perth, WA 6102, Australia
R. M. Clarke
Affiliation:
ChemCentre, PO Box 1250, Bentley, WA 6983, Australia
J. A. Kimpton
Affiliation:
Australian Synchrotron, 800 Blackburn Road, Clayton, Vic 3168, Australia
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The orthorhombic mineral moolooite, CuC2O4. nH2O, described by Clarke and Williams (1986) using Debye-Scherrer photographic data, has a fully-disordered stacking fault (FDSF) structure. Related monoclinic models have been reported for various synthesised samples based on Schmittler (1968). In the present study, synchrotron radiation diffraction data for moolooite and synthesised specimens have been examined with particular reference to crystallographic disorder. The moolooite data correspond to space group Pnnm, with a = 5.3064(2), b = 5.6804(2), c = 2.5630(1) Å; Vc = 77.26(1) Å3; and Z = 1; and the FDSF structure along the b-direction has been confirmed. The synthetic specimen data from the study indicate partial ordering, with space group P21/n; and the cell parameters for one specimen being a = 5.957(7), b = 5.611(5), c = 5.133(7) Å; β = 115.16(2)°; Vc = 155.27 Å3 and Z = 2. The level of zeolitic water in the materials has been considered using the approach of Schmittler based on thermogravimetry and pycnometry. The new data for natural topotype material correspond to CuC2O4.1.0H2O. It is postulated that the level of water for natural and synthetic specimens may be attributed to the conditions under which the material forms.

Type
Technical Article
Copyright
Copyright © International Centre for Diffraction Data 2019 

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References

Chisholm, J. E. and Jones, G. C. and Purvis O. W. (1987). “Hydrated copper oxalate, moolooite, in lichens,” Mineral. Mag. 51, 715718.Google Scholar
Christensen, A. N., Lebech, B., Andersen, N. H., and Grivel, J-C. (2014). “The crystal structure of paramagnetic copper (II) oxalate (CuC2O4): formation and thermal decomposition of randomly-stacked anisotropic nano-sized crystallites,” Dalton T. 43, 1675416768.Google Scholar
Clarke, R. M. and O'Connor, B. H. (In progress). “New mineralogical data for moolooite and middlebackite from Mooloo Downs, Western Australia,” Mineral. Mag.Google Scholar
Clarke, R. M. and Williams, I. R. (1986). “Moolooite, a naturally occurring hydrated copper oxalate from Western Australia,” Mineral. Mag. 50, 295298.Google Scholar
Elliott, P. (2016). “Middlebackite, IMA 2015-115,” CNMNC Newsletter No 30, April 2016, page 411; Mineral. Mag. 80, 407413.Google Scholar
Elliott, P. (2018). “Middlebackite, a new Cu oxalate mineral from Iron Monarch, South Australia: description and crystal structure,” Pre-proof accepted article, Mineral. Mag. DOI: 10.1180/mgm.2018.136.Google Scholar
Fichtner-Schmittler, H. (1979). “On some features of x-ray powder patterns of OD structures,” Cryst. Res. Technol. 14, 10791088.Google Scholar
Fichtner-Schmittler, H. (1984). “Comments on the structure of copper (II) oxalate: discussion of x-ray powder diffraction and EXAFS results as a basis for interpretation of magnetic properties,” Cryst. Res. Technol. 19, 12251230.Google Scholar
Frost, R. L., Erickson, K., and Weier, M. (2004). “Thermal treatment of moolooite – a high resolution thermogravimetric and hot stage Raman spectroscopic study,” J. Therm. Anal. Calorim. 77, 851861.Google Scholar
Gleizes, A., Maury, F., and Galy, J. (1980). “Crystal structure and magnetism of sodium bis(oxalate)cuprate(II) dihydrate, Na2Cu(C2O4)2.2H2O. A deductive proposal for the structure of copper oxalate, CuC2O4. xH2O (0 ≤ x<1),” Inorg. Chem. 19, 20742078.Google Scholar
Hill, R. J. and Flack, H. D. (1987). “The use of the Durbin-Watson d statistic in Rietveld analysis,” J. Appl. Crystallog. 20, 356361.Google Scholar
ICDD (2016). PDF-4 + 2016 (Database), edited by Kabekkodo, S. (International Centre for Diffraction Data, New Town Square, PA, USA).Google Scholar
International Tables for X-ray Crystallography (1995). Vol C: Mathematical, Physical and Chemical Tables, edited by Wilson, A.J.C. (Kluwer Academic Publishers, Dordrecht), pp. 707791.Google Scholar
Kondrashev, Y. D., Bogdanov, V. S., Golubev, S. N., and Pron, G. F. (1985). “Crystal structure of the ordered phase of zinc oxalate and the structure of anhydrous Fe2+, Co2+. Ni2+, Cu2+ and Zn2+ oxalates,” J. Struct. Chem. 26, 9093.Google Scholar
Michalowicz, A., Girerd, J. J., and Goulon, J. (1979). “EXAFS determination of the copper oxalate structure. Relation between structure and magnetic properties,” Inorg. Chem. 18, 30043010.Google Scholar
O'Connor, B. H. and Maslen, E. N. (1966). “The crystal structure of copper(II) succinate dihydrate,” Acta Crystallogr. 20, 824835.Google Scholar
O'Connor, B. H., Clarke, R. M., and Kimpton, J. A. (In progress). “Synchrotron radiation study of middlebackite [Cu2C2O4(OH)2] using a mineral specimen from Moolooo Downs, Western Australia and chemically synthesized material,” Powder Diffr.Google Scholar
Schmitt, B., Bronnimann, C, Eikenberry, E. F., Gozzo, F., Horrmann, C., Horisberger, R., and Patterson, B. (2003). “Mythen detector system,” Nucl. Instrum. Methods Phys. Res., Sect. A 501, 267272.Google Scholar
Schmittler, H. (1968). “Structural principles of disordered copper(II) oxalate (CuC2O4. nH2O),” Monatsber. Deut. Akad. Wiss. Berlin 10, 581604.Google Scholar
Wu, W-Y and Zhai, L-X (2007). “Poly[diaqua-μ-oxalato-copper(II) monohydrate,” Acta Crystallogr., Sect. E: Struct. Rep. Online, m249-m430.Google Scholar
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