Helical twisting power and circular dichroism as chirality observations - Development of a sector rule for the intermolecular chirality transfer in aliquid crystal phase

Any chirality measurements, e.g. circular dichroism (CD) or helical twistin g power (HTP), should offer a possibility to develop a method for the deter mination of the absolute configuration. Measurements of CD and optical rota tory dispersion (ORD) have been used as standard methods for decades. Since the HTP is very sensitive to variations in the molecular structure, the qu estion of the conditions under which determination of HTP can also be used as a method for the determination of the absolute configuration has been an alyzed. It has been found, that a sector rule can be developed for a specif ic class of compounds. A quadrant or octant rule can be applied successfull y for mono- and bis-aminoanthraquinones, as has been shown by a correlation of HTP with the CD of the long-wavelength charge transfer band. However, a rule of this type breaks down for compounds with low HTP and CD values.