MAGNETIC-FIELD ORIENTATION OF THE LIQUID-CRYSTALS OF POLYRIBONUCLEOTIDE COMPLEXES

Small-angle laser light scattering and double refractive index measurements on the nematic solutions of poly(A)-poly(U) and poly(A)-2poly(U) have been carried out in static magnetic fields and the data have been discussed in terms of alignment of rodlike molecular clusters having induced, magnetic dipole moments. It has been suggested that these polyribonucleotide complexes are diamagnetic and their maximum magnetic susceptibilities are in the direction parallel to the axes of polymer helices. Best agreement with the measurements is obtained assuming that certain wall effects of the optical cell and spacer, which is introduced into the optical cell, are involved.