In:
Acta Crystallographica Section C Structural Chemistry, International Union of Crystallography (IUCr), Vol. 74, No. 1 ( 2018-01-01), p. 69-74
Abstract:
The Z and E isomers of 3-[4-(dimethylamino)phenyl]-2-(2,4,6-tribromophenyl)acrylonitrile, C 17 H 13 Br 3 N 2 , ( 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 P 2 1 / n , Z ′ = 1), whereas the ( E )-( 1 ) isomer is triclinic (space group P \overline{1}, 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\overline{1}). 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 ).
Type of Medium:
Online Resource
ISSN:
2053-2296
DOI:
10.1107/S2053229617017648
DOI:
10.1107/S2053229617017648/ky3133sup1.cif
DOI:
10.1107/S2053229617017648/ky3133Eacrylsup2.hkl
DOI:
10.1107/S2053229617017648/ky3133Zacrylsup3.hkl
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2018
detail.hit.zdb_id:
2025703-X
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