Hyperpolarizability and polarizability enhancement in ferrocene–quinacridone systems: structural and photophysical perspectives through DFT and molecular simulation
摘要
Research on designing compounds with effective nonlinear optics responsiveness is fascinating. The present research examines how quinacridone can improve nonlinear optical characteristics in conjugated D-π-A and D-π-A-π-A systems based on ferrocene. Through an analysis of the photophysical behavior, theoretical calculations, and structural features, we uncover notable increases in higher-order hyperpolarizabilities (β, γ) and polarizability (α). New quinacridone-based (FR1-FR8) compounds are designed with the demand and uses of NLO materials in mind. The Nd:-YAG laser with a fundamental wavelength of 1064 nm is used to calculate the frequency-dependent NLO response of R (ferrocene as donor and cyanovinylene as acceptor with phenyl as π-spacer) compound. The theoretical calculation of the absorption maximum λmax of reference compound (R) was 389 nm, while the experimental calculation was 365 nm. The experimental calculation produced Eg = 2.76 eV, but the theoretical prediction of the energy gap of R was Eg = 2.98 eV. The theoretical and actual values of β frequency-dependent second-harmonic generation (SHG) for R were 1.46 × 10–30 esu and 10.49 × 10–30 esu, respectively. The CAM (Coulomb-attenuating method)-B3LYP functional with gen 6-311G (d,p)//cc-pVDZ basis set was utilized for additional theoretical investigation because the results were close to the experimental results. Every chemical from FR1 to FR6 was exhibiting an improved NLO response. Their β values increased from 208.92 × 10–30 to 6822.86 × 10–30 esu, while their energy gap Eg decreased from 2.38 to 1.40 eV. γ values were also computed to support the NLO response. With a maximum β = 6822.86 × 10–30 esu, FR7 was deemed the most appropriate material for NLO response out of all the designed derivatives. Thus, quinacridone has been used to improve nonlinear optical responses by stabilizing the electronic state and facilitating intramolecular charge transfer. Our results imply that novel materials with improved performance for optical applications can be designed by utilizing the synergistic impact of ferrocene and quinacridone.
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