The molecular hyperpolarizability γ(-ω;ω,ω,-ω) of a supramolecule, zinc 4,4[sup ′] ,4[sup ′′] ,4[sup ′′′] -tetrasulfonato-phthalocyanine/N-butyl-N[sup ′] -methylanthraquinone-4,4[sup ′] -bipyridinum dibromide assembly (ZnTsPc-V-AQ), was observed to be enhanced by ten times when the sample was optically pumped by a 355 nm pump beam. The enhancement of the nonlinearity was found to be due predominantly to the charge transfer between the two monomers of the supramolecule after optical excitation. [ABSTRACT FROM AUTHOR]