Br…Br and van der Waals interactions along a homologous series: crystal packing of 1, 2‐dibromo‐4, 5‐dialkoxybenzenes. Issue 5 (16th September 2016)

• Record Type: Journal Article
• Authors: Suarez, Sebastián A.; Muller, Federico; Gutiérrez Suburu, Matías E.; Fonrouge, Ana; Baggio, Ricardo F.; Cukiernik, Fabio D.
• Is Part Of: Acta crystallographica. Volume 72:Issue 5(2016:Oct.)
• Page Start: 693
• Page End: 701
• Publication Date: 2016-09-16
• Subjects: chemical crystallography -- 1, 2‐dibromo‐4, 5‐dialkoxybenzenes -- halogen bonds -- crystal engineering
• DOI: 10.1107/S2052520616009835
• Languages: English
• ISSNs: 2052-5206

Abstract

Abstract : The crystalline structures of four homologues of the 1, 2‐dibromo‐4, 5‐dialkoxybenzene series [Br2 C6 H2 (OC n H2 n + 1 )2 for n = 2, 12, 14 and 18] have been solved by means of single‐crystal crystallography. Abstract : The crystalline structures of four homologues of the 1, 2‐dibromo‐4, 5‐dialkoxybenzene series [Br2 C6 H2 (OC n H2 n + 1 )2 for n = 2, 12, 14 and 18] have been solved by means of single‐crystal crystallography. Comparison along the series, including the previously reported n = 10 and n = 16 derivatives, shows a clear metric trend (b andc essentially fixed along the series anda growing linearly with n ), in spite of some subtle differences in space groups and/or packing modes. A uniform packing pattern for the aliphatic chains has been found for the n = 12 to 18 homologues, which slightly differs from that of the n = 10 derivative. The crystalline structures of all the higher homologues ( n = 10–18) seem to arise from van der Waals interchain interactions and, to a lesser extent, type II Br…Br interactions. The dominant role of interchain interactions provides direct structural support for the usual interpretation of melting point trends like that found along this series. Atoms in Molecules (AIM) analysis allows a comparison of the relative magnitude of the interchain and Br…Br interactions, an analysis validated by the measured melting enthalpies.