Title of article :
Crystal structure of tetramethylammonium 1,1,7,7-tetracyanohepta-2,4,6-trienide
Author/Authors :
Bogdanov, Georgii Department of Chemistry - New Mexico Highlands University, USA , Bustos, Jenna Department of Chemistry - New Mexico Highlands University, USA , Tillotson, John P School of Chemistry and Biochemistry - Georgia Institute of Technology, USA , Fonari, Marina Department of Chemistry - New Mexico Highlands University, USA , Timofeeva, Tatiana V. Department of Chemistry - New Mexico Highlands University, USA
Abstract :
The title compound, C4H12N+ C11H5N4 , contains one tetramethylammonium
cation and one 1,1,7,7-tetracyanohepta-2,4,6-trienide anion in the asymmetric
unit. The anion is in an all-trans conjugated C C bonds conformation. Two
terminal C(CN)2 dinitrile moieties are slightly twisted from the polymethine
main chain to which they are attached [C(CN)2/C5 dihedral angles = 6.1 (2) and
7.1 (1)]. The C—C bond distances along the heptadienyl chain vary in the
narrow range 1.382 (2)–1.394 (2) A˚ , thus indicating the significant degree of
conjugation. In the crystal, the anions are linked into zigzag chains along the
[101] direction by C—HN(nitrile) short contacts. The antiparallel chains stack
along the [110] direction with alternating separations between the neighboring
anions in stacks of 3.291 and 3.504 A˚ . The C—HN short contacts and stacking
interactions combine to link the anions into layers parallel to the (101) plane and
separated by columns of tetramethylammonium cations.
Keywords :
crystal structure , polymethines , carbanion , hepta-2,4,6-triene-1,1,7,7-tetracarbonitrile , weak interactions , stacking
Journal title :
Acta Crystallographica Section E: Crystallographic Communications
