Both steady state and time resolved spectroscopic investigations on a novel synthesized bichromophore 4MBA (4 methoxybenzo[b]thiophene donor (4MBT) is linked with the electron acceptor p-chloroacetophenone (PCA) by an unsaturated olefinic spacer) in aqueous medium demonstrate the formation of two types of isomer. One is due to cis(folded conformation) and the other corresponds to trans- (extended nature) resulted from intramolecular charge separation reactions both in the ground and excited electronic states. Laser flash photolysis measurements show that the preponderance of trans-type isomer of 4MBA in presence of beta-cyclodextrin, due to formation of inclusion complexes, causes the enhancement of the survival duration of charge separated species to large extent (66 mus) minimizing the energy wasting charge recombination process. (C) 2003 Elsevier B.V. All rights reserved.