Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state of exocyclic double...Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state of exocyclic double bond (ECDB) conjugated bridge by the optimization of the substituted method, and their electronic and second-order nonlinear optical properties have been theoretically investigated by employing the AM1/FF and ZINDO/S-CI approaches. By extending the conjugation length and optimizing the donor/acceptor strength, the oscillator strength of the excited transition that contributes to the molecular nonlinearity can be further enhanced. The designed chromophores possess a larger figure of merit (FOM) than that of 4-N,N-dimethylamino-4’-nitrostilbene (DANS), and lower (5 D) ground state dipole moment.Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state展开更多
The nonlinear optical properties of title compounds calculated by AM1/finite field (AM1/FF) approach are discussed based on their crystal parameters. The origins of large molecular first hyperpolarizahilitiesβ and go...The nonlinear optical properties of title compounds calculated by AM1/finite field (AM1/FF) approach are discussed based on their crystal parameters. The origins of large molecular first hyperpolarizahilitiesβ and good transparency of the compounds are explained well through the aromatic character enhancement in the excited state and the short conjugation length in the ground state. Results show that the difference ofβ values obtained by two experimental methods (Solvatochromic and Hyper Rayleigh Scattering) is due to the molecular quasi-two-dimension character and the octupolar components’ contribution. The calculation has also demonstrated that the change ofγ xxx caused by different donor substituents is linearly related with the Hammett substituent constant σ+.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 59790050, 29704009 and 59973024).
文摘Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state of exocyclic double bond (ECDB) conjugated bridge by the optimization of the substituted method, and their electronic and second-order nonlinear optical properties have been theoretically investigated by employing the AM1/FF and ZINDO/S-CI approaches. By extending the conjugation length and optimizing the donor/acceptor strength, the oscillator strength of the excited transition that contributes to the molecular nonlinearity can be further enhanced. The designed chromophores possess a larger figure of merit (FOM) than that of 4-N,N-dimethylamino-4’-nitrostilbene (DANS), and lower (5 D) ground state dipole moment.Novel low dipole moment (μ) and large first hyperpolarizability (β) electrooptic chromophores have been designed based on the special characteristic of reversed dipole moment in the excited state
文摘The nonlinear optical properties of title compounds calculated by AM1/finite field (AM1/FF) approach are discussed based on their crystal parameters. The origins of large molecular first hyperpolarizahilitiesβ and good transparency of the compounds are explained well through the aromatic character enhancement in the excited state and the short conjugation length in the ground state. Results show that the difference ofβ values obtained by two experimental methods (Solvatochromic and Hyper Rayleigh Scattering) is due to the molecular quasi-two-dimension character and the octupolar components’ contribution. The calculation has also demonstrated that the change ofγ xxx caused by different donor substituents is linearly related with the Hammett substituent constant σ+.
