The Conformation of Biphenyls in Nematic Liquid Crystalline Solution. The Relationship between the Torsional Angles and the Size of the Halogens in 2,6-Dihalogenated Derivatives

Article abstract of DOI:10.1021/ja00394a002

Analysis of the NMR spectrum of 4'-bromo-4-chloro-2,6-difluorobiphenyl in a nematic liquid crystalline solvent, together with the previously reported work of Field, Sternhell, and Tracey shows that the ground-state torsional angles in this series are a smooth monotonic function of the size of the halogens at C-2 and C-6.There are indications that through-conjugation plays a very minor role in determining the torsional angles and that results of this type could be used as an independent method of determining some van der Waals radii.