Order parameters and refractive indices of some cyano-benzoate nematic liquid crystals with high transition temperatures

► The tail group in investigated LCs controls variations of refractive indices, birefringence and order parameter. ► All investigated LCs show good agreement between the values obtained via curve fitting and the experimental results. ► In studied LCs macroscopic and microscopic order parameters show good agreement. ► In investigated liquid crystals the values of scaling factors control order parameter amount.