Acta Crystallographica Section C

Crystal Structure Communications

Volume 64, Part 3 (March 2008)

organic compounds

 

13-cis-,-Carotene and 15-cis-,-carotene

G. Bartalucci, C. Delroy, S. Fisher, M. Helliwell and S. Liaaen-Jensen

Abstract: 13-cis-,-Carotene, C₄₀H₅₆, crystallizes with a complete molecule in the asymmetric unit, whereas 15-cis-,-carotene, also C₄₀H₅₆, has twofold symmetry about an axis through the central bond of the polyene chain. The polyene methyl groups are arranged on one side of the polyene chains for each molecule and the 6-s-cis end groups, with the cyclohexene rings in half-chair conformations, are twisted out of the planes of the polyene chains by angles ranging from 41.37 (17) to 52.2 (4)°. The molecules in each structure pack so that the arms of one occupy the cleft of the next, and there is significant - stacking of the almost-parallel polyene chains of the 15-cis isomer, which approach at distances of 3.319 (1)-3.591 (1) Å.

Formula: Two isomers of C₄₀H₅₆

	Structure factor file (CIF format) (286.8 kbytes) [ doi:10.1107/S0108270108001583/jz3117Isup2.hkl ] Contains datablock I
	Structure factor file (CIF format) (169.3 kbytes) [ doi:10.1107/S0108270108001583/jz3117IIsup3.hkl ] Contains datablock II

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.

Copyright © International Union of Crystallography
IUCr Webmaster