Z/E-Isomerism of 3-[4-(dimethylamino)phenyl]-2-(2,4,6-tribromophenyl)acrylonitrile: Crystal structures and secondary intermolecular interactions

The Z and E isomers of 3-[4-(dimethylamino)phenyl]-2-(2,4,6-tribromophenyl)acrylonitrile, C17H13Br3N2, (1), were obtained simultaneously by a Knoevenagel condensation between 4-(dimethylamino)benzaldehyde and 2-(2,4,6-tribromophenyl)acetonitrile, and were investigated by X-ray diffraction and density functional theory (DFT) quantum-chemical calculations. The (Z)-(1) isomer is monoclinic (space group P21/n, Z′ = 1), whereas the (E)-(1) isomer is triclinic (space group P, Z′ = 2). The two crystallographically-independent molecules of (E)-(1) adopt similar geometries. The corresponding bond lengths and angles in the two isomers of (1) are very similar. The difference in the calculated total energies of isolated molecules of (Z)-(1) and (E)-(1) with DFT-optimized geometries is ∼4.47 kJ mol-1, with the minimum value corresponding to the Z isomer. The crystal structure of (Z)-(1) reveals strong intermolecular nonvalent Br···N [3.100 (2) and 3.216?(3)?Å] interactions which link the molecules into layers parallel to (10). In contrast, molecules of (E)-(1) in the crystal are bound to each other by strong nonvalent Br···Br [3.5556 (10) Å] and weak Br···N [3.433 (4) Å] interactions, forming chains propagating along [110]. The crystal packing of (Z)-(1) is denser than that of (E)-(1), implying that the crystal structure realized for (Z)-(1) is more stable than that for (E)-(1). © 2018 International Union of Crystallography.

Authors
Tammisetti R.D.1 , Kosilkin I.V.1 , Guzei I.A. 2, 3 , Khrustalev V.N. 3 , Dalton L.4 , Timofeeva T.V.1
Publisher
International Union of Crystallography
Number of issue
1
Language
English
Pages
69-74
Status
Published
Volume
74
Year
2018
Organizations
  • 1 Chemistry Department, New Mexico Highlands University, PO Box 9000, Las Vegas, NM 87701, United States
  • 2 Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI 53558, United States
  • 3 Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklay St., Moscow, 117198, Russian Federation
  • 4 Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, United States
Keywords
acrylonitrile; crystal structure; DFT calculations; E/Z isomers; secondary Br···N and Br···Br interactions
Date of creation
19.10.2018
Date of change
19.10.2018
Short link
https://repository.rudn.ru/en/records/article/record/7107/
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