K. Kandasamy, Shankar J. Shetty, P. N. Puntambekar, T. S. Srivastava, T. Kundu and Bhanu P. Singh
Non-resonant second molecular hyperpolarisabilities (γ) of tetraphenylporphyrin (H2tpp) and five substituted derivatives are measured by the Z-scan technique at 784 nm; the relationship between the various structures and their corresponding molecular hyperpolarisabilities is explained on the basis of electronic interaction between the external substituents and the porphyrin core.