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Stacking patterns of thieno[3,2‐ b ]thiophenes functionalized by sequential palladium‐catalyzed Suzuki and Heck cross‐coupling reactions
Author(s) -
Nguyen Hien,
Nguyen Bich Ngan,
Dang Tung T.,
Van Meervelt Luc
Publication year - 2014
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229614018683
Subject(s) - thiophene , moiety , chemistry , substituent , steric effects , stacking , suzuki reaction , palladium , stereochemistry , benzothiophene , ring (chemistry) , aromaticity , molecule , catalysis , organic chemistry
The crystal structures of three 5‐alkenyl‐2‐arylthieno[3,2‐ b ]thiophenes, namely 3,6‐dibromo‐5‐(4‐ tert ‐butylstyryl)‐2‐(naphthalen‐1‐yl)thieno[3,2‐ b ]thiophene, C 28 H 22 Br 2 S 2 , (I), 3,6‐dibromo‐5‐(4‐methylstyryl)‐2‐(naphthalen‐1‐yl)thieno[3,2‐ b ]thiophene, C 25 H 16 Br 2 S 2 , (II), and 3,6‐dibromo‐2‐(4‐ tert ‐butylphenyl)‐5‐(4‐methylstyryl)thieno[3,2‐ b ]thiophene, C 25 H 22 Br 2 S 2 , (III), have been determined in order to evaluate the geometry of the molecules. The π‐conjugated system containing the thieno[3,2‐ b ]thiophene skeleton, the ethylene bridge and the phenyl rings is almost planar. The aromatic ring directly attached to the thieno[3,2‐ b ]thiophene moiety is not coplanar with the thieno[3,2‐ b ]thiophene moiety itself due to steric hindrance of the bromo substituent. The crystal packings are characterized by π–π stacking [only for (II)] and C—Br...π interactions. The long axes of the molecules in (I) are oriented in two directions; for the two other structures the long axis is oriented in one direction only.