The structure of substituted biphenyls as studied by proton NMR in nematic solvents. Single conformation model versus maximum entropy analysis

Abstract

Published [11,12] proton nuclear magnetic resonance data for two substituted biphenyl molecules dissolved in nematic solvents are analysed in terms of the single conformation model and compared with the results of the maximum entropy analysis of [11]. It is shown that (i) this model, in which the number of adjustable parameters is less than the number of data, can describe very well the data for both molecules and (ii) the results of the maximum entropy analysis provide global support for this model. It is argued that the ultimate support of the single conformation model would be that introduction of a sufficiently large number of additional data in the maximum entropy analysis leads to a distribution for the dihedral angle between the two phenyl rings with two symmetrical very sharp peaks.