The Influence of the Side Chain Length on −OCH3−π Interactions Determining the Crystal Packing of Four Substituted 1,4-Bis(α-styryl)benzenes

• Published in: Crystal growth & design 2004-07, Vol.4 (4), p.823-830
• Main Authors: Vande Velde, Christophe M. L, Chen, Li-Juan, Baeke, Jan K, Moens, Maarten, Dieltiens, Pieter, Geise, Herman J, Zeller, Matthias, Hunter, Allen D, Blockhuys, Frank
• Format: Article
• Language: English
• Subjects: Aliphatic, non-condensed and condensed benzenic, and alicyclic compounds; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg0499764

The crystal structures of E,E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-dimethoxybenzene (1), E,E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-diisopropoxybenzene (2), E,E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-dihexoxybenzene (3), and E,E-1,4-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]-2,5-bis(2-phenylethoxy)benzene (4) are reported. A weak intramolecular hydrogen bond between protons on the olefinic link and the ortho-methoxy groups on the adjacent benzene rings is commented on. In general, however, the crystal packing for these structures is primarily determined by weak −OCH3−π interactions. Their numbers change with the structure and length of the side chains and with the accommodation of the extended chains in the lattice. A discussion on the effects of these interactions on the possibility of lattice formation explains why these four compounds crystallize and several similar ones with different alkoxy side chains do not.