Photophysical studies of fused phenanthrimidazole derivatives as versatile π-conjugated systems for potential NLO applications

► Non-zero dipole moment, hyperpolarizabilities shows well microscopic NLO behavior. ► Second order Fock matrix to evaluate the donor-acceptor interactions in NBO analysis. ► The ρ values reveal that βiii component cannot be zero and these are dipolar component. ► HOMO-LUMO: probable charge transfer (CD) taking place inside the chromophore. ► Bar diagram: the charge distribution calculated by NLO and NBO analysis.