EXCITON COUPLING IN VARIOUS SUBSTITUTED ARYL-PHTHALIMIDE BICHROMOPHORIC SYSTEMS

As demonstrated in this paper, exciton Cotton effects reflecting the a bsolute stereochemistry of the molecule can result from coupling betwe en the allowed transitions of phthalimide. 3,6-dichlorophthalimide. 4, 5-dichlorophthalimide or 3,4,5,6-tetrachlorophthalimide and p-substitu ted benzene, naphthalene. benzoate or cinnamate chromophores. This sig nificantly extends the scope of application of phthalimide chromophori c derivatives to stereochemical assignments by CD spectroscopy. The di rection of the transition moments in chlorinated phthalimide chromopho res are determined from linear dichroism measurements of N-butyl deriv atives oriented in polyethylene film. Copyright (C) 1996 Published by Elsevier Science Ltd.