Acta Crystallographica Section B

Volume 65, Part 4 (August 2009)

research papers

Acta Cryst. (2009). B65, 481-487 [ doi:10.1107/S0108768109023489 ]

Structures of strontium diformate and strontium fumarate. A synchrotron powder diffraction study

K. Ståhl, J. E. T. Andersen, I. Shim and S. Christgau

Abstract: The crystal structures of strontium diformate in space groups P2₁2₁2₁ ( [alpha] form, 295 K), P4₁2₁2 ( [beta] form, 334 and 540 K) and I4₁/amd ( [delta] form, 605 K), and strontium fumarate in space groups Fddd ( [beta] form, 105 K) and I4₁/amd ( [alpha] form, 293 K) have been determined from synchrotron X-ray powder diffraction data. Except for the [alpha] -strontium diformate, all the structures are based on a diamond-like Sr-ion arrangement, as in strontium acetylene dicarboxylate. The formate ions are disordered in the [delta] phase owing to steric hindrance. The fumarate ions are disordered over four ( [alpha] ) or two ( [beta] ) symmetry-equivalent orientations. [alpha] -Strontium fumarate crystallizes with a unique 90° carboxylate dihedral angle, and is stable up to 773 K.

Keywords: synchrotron X-ray powder diffraction; phase transitions.


	Rietveld powder data file (CIF format) (808.0 kbytes) [ doi:10.1107/S0108768109023489/zb5005alphastrontiumdiformate293Ksup2.rtv ] Contains datablock alphastrontiumdiformate293K

	Rietveld powder data file (CIF format) (808.1 kbytes) [ doi:10.1107/S0108768109023489/zb5005betastrontiumdiformate334Ksup3.rtv ] Contains datablock betastrontiumdiformate334K

	Rietveld powder data file (CIF format) (808.0 kbytes) [ doi:10.1107/S0108768109023489/zb5005betastrontiumdiformate540Ksup4.rtv ] Contains datablock betastrontiumdiformate540K

	Rietveld powder data file (CIF format) (808.0 kbytes) [ doi:10.1107/S0108768109023489/zb5005deltastrontiumdiformate605Ksup5.rtv ] Contains datablock deltastrontiumdiformate605K

	Rietveld powder data file (CIF format) (817.2 kbytes) [ doi:10.1107/S0108768109023489/zb5005alphastrontiumfumarate293Ksup6.rtv ] Contains datablock alphastrontiumfumarate293K

	Rietveld powder data file (CIF format) (817.2 kbytes) [ doi:10.1107/S0108768109023489/zb5005betastrontiumfumarate105Ksup7.rtv ] Contains datablock betastrontiumfumarate105K

Notes:

To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

Search: From to Advanced search