Computational study of the one- and two-photon absorption properties of macrocyclic thiophene derivatives

摘要

The geometrical structure, electronic structure, one-photon and two-photon absorption properties of a series of macrocyclic thiophene derivatives C[3T_DA]_n (n = 2-5) have been studied using density functional theory (DFT) and Zerner's intermediate neglect of differential overlap (ZINDO) methods theoretically. The results showed that the range of λ_(maxS)~((1)) is 390-470 nm and A_(maxS)~((2)) is 640-670 nm, while, both λ_(max)~((1)) and λ_(max)~((2)) gradually enlarge as increasing the number of the C[3T_DA] unit. And C [3T_DA]_n compounds exhibited large TPA cross-section (δ_(max)), and the factors influencing on the δ_(max) values were analyzed in detail. Transition dipole moments M_(0k) and M_(kn) play important roles on δ_(max). Both π-electron number (N_e) and the product of oscillator strengths from ground state to mediate state (f_(0k)) and from mediate state to final state (f_(kn)) are in proportion to δ_(max). Moreover, δ_(max) linearly depends on the static second-order nonlinear optical susceptibilities (β0).