Determination of the local field anisotropy and order parameter for 4-alkyl-4 '-alkoxytolans from refractometric data

Based on the temperature dependences of the refractive indices and refracti on for low-polarity nematic tolan derivatives, the Lorentz tenser, order pa rameter, and local field anisotropy tenser are derived. For the first time, the dependence of these parameters on the configurations of the alkyl and alkoxy substituents attached to a linear rigid molecule was considered. For some of the configurations, anomalous changes in the local field anisotrop y were revealed. The order parameter calculated for nematic LCs with consid eration for the local field is smaller than without such consideration.