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Local structure in the disordered solid solution of cis ‐ and trans ‐perinones
Author(s) -
Teteruk Jaroslav L.,
Glinnemann Jürgen,
Heyse Winfried,
Johansson Kristoffer E.,
van de Streek Jacco,
Schmidt Martin U.
Publication year - 2016
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520616004972
Subject(s) - crystal structure , crystallography , lattice energy , molecule , solid solution , chemistry , crystal (programming language) , anisotropy , lattice (music) , cis–trans isomerism , superposition principle , materials science , stereochemistry , physics , optics , quantum mechanics , organic chemistry , computer science , acoustics , programming language
The cis ‐ and trans ‐isomers of the polycyclic aromatic compound perinone, C 26 H 12 N 4 O 2 , form a solid solution (Vat Red 14). This solid solution is isotypic to the crystal structures of cis ‐perinone (Pigment Red 194) and trans ‐perinone (Pigment Orange 34) and exhibits a combined positional and orientational disorder: In the crystal, each molecular position is occupied by either a cis ‐ or trans ‐perinone molecule, both of which have two possible molecular orientations. The structure of cis ‐perinone exhibits a twofold orientational disorder, whereas the structure of trans ‐perinone is ordered. The crystal structure of the solid solution was determined by single‐crystal X‐ray analysis. Extensive lattice‐energy minimizations with force‐field and DFT‐D methods were carried out on combinatorially complete sets of ordered models. For the disordered systems, local structures were calculated, including preferred local arrangements, ordering lengths, and probabilities for the arrangement of neighbouring molecules. The superposition of the atomic positions of all energetically favourable calculated models corresponds well with the experimentally determined crystal structures, explaining not only the atomic positions, but also the site occupancies and anisotropic displacement parameters.