Roles of various bridges on intramolecular charge Transfers, dipole moments and first hyperpolarizabilities of Donor-Bridge-Acceptor types of organic Chromophores: Theoretical assessment using Two-State model

Donor-Bridge-Acceptor (D-B-A) types of push–pull organic molecules are generally considered as suitable functional materials for various technological applications. Properties of these molecules are strongly influenced by intramolecular charge transfers (ICT), where the ICT processes are controlled by bridges connecting the D and A. Many earlier studies investigated the effects some bridges on nonlinear optical (NLO) properties. But, no systematic comparative investigation with all well-known bridges studied at one place exist in the literature. Motivated by many earlier works, this work reports a theoretical assessment of the roles of various bridges on NLO properties for a set of D-B-A types of organic molecules, with same D/A combinations. Results for conjugated, non-conjugated and heteroatom substituted bridges were found to be showing interesting behaviours. This contribution can be expected to serve as a reference for many researchers working in the search of new and efficient functional materials.