Relative influence of noncovalent interactions on the melting points of a homologous series of 1,2-dibromo- 4,5-dialkoxybenzenes
Crystal structures are presented for two members of the homologous series of 1,2-dibromo-4,5-dialkoxybenzenes, viz. those with decyloxy and hexadecyloxy substituents, namely 1,2-dibromo-4,5-bis(decyloxy)benzene, C26H44Br2O2, (II), and 1,2-dibromo-4,5-bis(hexadecyloxy)benzene, C38H68Br2O2, (III). The...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2013 |
| País: | Argentina |
| Institución: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repositorio: | Biblioteca Digital (UBA-FCEN) |
| Idioma: | inglés |
| OAI Identifier: | paperaa:paper_01082701_v69_n2_p204_Fonrouge |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_01082701_v69_n2_p204_Fonrouge |
| Access Level: | acceso abierto |
| Palabra clave: | Aliphatic chains Crystal stability Dimethoxybenzene Halogen bonding Homologous series Non-covalent interaction Van der Waals contacts Van Der Waals interactions Benzene Iodine Ions Melting point Van der Waals forces Bromine |
| Sumario: | Crystal structures are presented for two members of the homologous series of 1,2-dibromo-4,5-dialkoxybenzenes, viz. those with decyloxy and hexadecyloxy substituents, namely 1,2-dibromo-4,5-bis(decyloxy)benzene, C26H44Br2O2, (II), and 1,2-dibromo-4,5-bis(hexadecyloxy)benzene, C38H68Br2O2, (III). The relative influences which halogen bonding, π- π stacking and van der Waals interactions have on these structures are analysed and the results compared with those already found for the lightest homologue, 1,2-dibromo-4,5- dimethoxybenzene, (I) [Cukiernik, Zelcer, Garland & Baggio (2008). Acta Cryst. C64, o604-o608]. The results confirm that the prevalent interactions stabilizing the structures of (II) and (III) are van der Waals contacts between the aliphatic chains. In the case of (II), weak halogen C - Br ⋯(Br - C) ′ interactions are also present and contribute to the stability of the structure. In the case of (III), van der Waals interactions between the aliphatic chains are almost exclusive, weaker C - Br ⋯ π interactions being the only additional interactions detected. The results are in line with commonly accepted models concerning trends in crystal stability along a homologous series (as measured by their melting points), but the earlier report for n = 1, and the present report for n = 10 and 16, are among the few providing single-crystal information validating the hypothesis. |
|---|