Rigid Probe Solutes in a Smectic-A Liquid Crystal: an Unconventional Route to the Latter’s Positional Order Parameters

Biphenylene and pyrene were dissolved in the nematic and smectic-A phases of the liquid crystal 4,4'- di-n-heptyl-azoxybenzene and the orientational order parameters of both solutes and solvent measured via proton and deuteron nuclear-magnetic-resonance spectroscopy. This new data set was then merged with the one previously obtained, formed by 4,4'-di-chloro-benzene and naphthalene as solutes in the same solvent, and the resulting overall data set analyzed with a statistical thermodynamic density-functional theory to provide positional-orientational distribution functions of the various solutes along with the smectic solvent’s positional order parameters.