Nematic Order of APAPA from X-Ray Diffraction and Optical Studies

Anisylidene-p-aminophenyl acetate, a nematogenic Schiff's base, is studied by X-ray diffraction and optical methods. Orientational order parameters (P 2) and (P 4) of magnetically aligned samples have been calculated from X-ray diffraction photographs. Order parameters (P 2) have also been determined from refractive index measurements. (P 2) values obtained from both the methods agree well with the MS values while (P 4) values differ much. Average intermolecular distances and apparent molecular lengths have also been calculated.