Acta Crystallographica Section C

Crystal Structure Communications

Volume 57, Part 12 (December 2001)

Acta Cryst. (2001). C57, 1426-1428 [doi:10.1107/S0108270101015931]

Room-temperature monoclinic and low-temperature triclinic phase-transition structures of meso-octamethylcalix[4]pyrrole-dimethyl sulfoxide (1/1)

V. M. Lynch, P. A. Gale, J. L. Sessler and D. Madeiros

Abstract: Crystals of the title complex, C₂₈H₃₆N₄·C₂H₆OS, undergo a phase transition between room temperature and 198 K, as determined by X-ray diffraction techniques. A monoclinic form is observed at room temperature, while a triclinic modification is found at 198 K, with Z' changing from 1 to 2. Differential scanning calorimetry (DSC) of the calixpyrrole-dimethyl sulfoxide complex revealed a series of phase changes between 273 and 243 K. The transition from the room-temperature monoclinic form to the low-temperature triclinic form is reversible, as determined by changes in the cell dimensions from remeasuring selected reflections at room temperature and at temperatures below 223 K. The uncomplexed calix[4]pyrrole molecule shows no phase changes occurring between room temperature and 233 K, the low-temperature limit of the DSC.

Formula: C₂₈H₃₆N₄·C₂H₆OS

Online 6 December 2001


	PDF file (195.4 kbytes) Four supplementary figures

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.