Heterocyclic Donor Moiety Effect on Optical Nonlinearity Behavior of Chrysene-Based Chromophores with Push-Pull Configuration the Quantum Chemical Approach.

Organic-based nonlinear optical (NLO) materials may be used in many optical-electronic systems and other next-generation defense technologies. With the importance of NLO materials, a series of push-pull architecture (D-π-A) derivatives (-) were devised from through structural alteration of different efficient donor heterocyclic groups. Density functional theory-based computations were executed at the MPW1PW91/6-31G(d,p) level to explore the NLO behavior of the derivatives. To investigate the optoelectronic behavior of the said compounds, various analyses like the frontier molecular orbital (FMO), global reactivity parameters, density of state (DOS), absorption spectra (UV-vis), natural bond orbital, and transition density matrix (TDM) were performed. The derivatives have a smaller band gap (2.156-1.492 eV) and a larger bathochromic shift (λ = 692.838-969.605 nm) as compared to the reference chromophore (Δ = 2.306 eV and λ = 677.949 nm). FMO analysis revealed substantial charge conduction out of the donor toward the acceptor via a spacer that was also shown by TDM and DOS analyses. All derivatives showed promising NLO results, with the maximum amplitude of linear polarizability ⟨α⟩ and first (β) and second (γ) hyperpolarizabilities over their reference chromophore. contained the highest β (7.220 × 10 esu) and γ (1.720 × 10 esu) values corresponding with the reduced band gap (1.492 eV), representing potential futures for a large NLO amplitude. This structural modification through the use of various donors has played a significant part in achieving promising NLO behavior in the modified compounds.