Proton distance ratios and order tensor elements for several halobenzenes obtained in a lyotropic potassium laurate mesophase

Abstract

Proton distance ratios and elements of the order tensor are obtained from nuclear magnetic resonance spectra of chloro-, bromo-, and iodobenzene partially oriented in a potassium laurate lyotropic mesophase. Corrections for harmonic vibrations are applied and it is shown that even for proton distance ratios these corrections are significant. Furthermore, the effects of solvent on the ratios determined are comparable to the effect of the substituent. Particular attention to weighting of the dipolar coupling in the structural analysis is necessary if values are to be judged significant to 1 part in 10⁴. The elements of the order tensor are discussed in terms of the orienting influence of the interface and alkyl chains of the mesophase surfactant.