Theoretical study on the second‐order nonlinear optical properties of nonconjugated D‐π‐A chromophores

Abstract

Density functional theory calculations have been carried out on nonconjugated D--A chromophores to investigate the different electron donors and conjugated bridges effects on the molecular nonlinear optical response. The results show that the large second-order polarizability values can be achieved through careful combination of available electron donors, conjugated bridges for our studied nonconjugated D--A chromophores. The calculations also provide a clear explanation for the second-order polarizability changes from the standpoint of transition energies, oscillator strengths, electron density difference, and bond length alternation. Solvent effect has great influence on the second-order polarizability and electronic absorption spectrum. It is hoped that the results presented in this article will give some hints to the interrelated studies.

Tuning the absorption spectra and nonlinear optical properties of D‐π‐A azobenzene derivatives by changing the dipole moment and conjugation length: a theoretical study

“…The electronic structures of the studied systems were investigated by using the DFT with B3LYP25, 26 functions and 6–31 + G(d) basis set. For the same set of chromophores, the addition of diffusion basis sets in this work led to a slight improvement relative to those obtained by Yang et al 20. at the B3LYP/6–31G(d) level.…”

“…One promising strategy is to assemble the linear D‐ π ‐A dipolar units into some novel oligomers with various topologies, such as H‐shape, X‐shape, Y‐shape, U‐shape, Λ‐shape, and so on 11–15. Among them, the H‐shaped dimers and polymers have gained an increased attention 16–20. In 2006, Liu's group synthesized two series of NLO polymers, which combine two chromophores via an isolation spacer 16.…”

“…Yang et al . theoretically studied those H‐shaped azobenzene derivatives by using density functional theory (DFT) method at the 6–31G(d) level 20. Despite these advances in experimental and theoretical works, an understanding of the relationship between the electronic structure and absorption spectrum and NLO property in solutions is still lack.…”

Computational study of chiral molecules with high intrinsic hyperpolarizabilities

“…Theoretical investigations can design nonlinear optical materials and may provide avenues of experimental study [28,29]. Our group has also investigated a series of novel NLO materials [30][31][32][33][34].…”

Theoretical study of static (Hyper)polarizabilities of twisted intramolecular charge transfer chromophores

“…However, such tailoring on conventional Donor-p-Acceptor (D-p-A) NLO chromophores often leads to a decrease in thermal stability and optical transparency. A number of molecules with various special structures such as octupolar [14][15][16], zwitterionic [17][18][19][20][21][22], multidimensional chromophores [23][24][25][26][27][28][29][30][31][32][33][34][35], etc. has been designed or synthesized to optimize the NLO activities of organic chromophores.…”