Doping alkali metal ions and introducing electron donor groups to fulleropyrrolidine derivatives: Large second-order nonlinear optical responses.

The present study is focused on the nature of the structure-properties relationships of 2,5-diaryl fulleropyrrolidine derivatives. 2,5-diaryl fulleropyrrolidines modified by electron donor groups, and doped endohedrally with alkali metal ions (M@1-D , D = –CH 3 , –OCH 3 , –NH 2 ; M = Li⁺, Na⁺, K⁺) are designed and investigated. Surprisingly, the K@1-NH 2 shows remarkable NLO response. [Display omitted] • The 2,5-Diaryl fulleropyrrolidine derivatives are designed and investigated. • M@1-D shows remarkable NLO response compared to 1-D and M@1. • The K⁺@1-NH 2 possesses the largest β tot value of 4.58 × 10³ a.u.. • Uv–vis absorption spectrum explains tendency of the β tot value. The present study is focused on the nature of the structure-properties relationships of the 2,5-diaryl fulleropyrrolidine (1) derivatives by the density functional theory (DFT). 1 derivatives are designed and investigated, which are modified by electron donor groups and doped with alkali metal ions (1-D , M@1 and M@1-D , D = –CH 3 , –OCH 3 , –NH 2 ; M = Li⁺, Na⁺, K⁺). Surprisingly, M@1-D compounds show a remarkable NLO response compared to 1-D and M@1. The K⁺@1-NH 2 possesses the largest β tot value of 4.58 × 10³ a.u.. Furthermore, the Uv–vis absorption spectrum by the time-dependent (TD-DFT) method is carried out to study tendency of the NLO responses for 1-D , M@1 and M@1-D. Calculated maximum absorption wavelength of K⁺@1-NH 2 is significantly red-shifted compared to 1-NH 2 and K⁺@1. The current work presents that 2,5-diaryl fulleropyrrolidine modified by introducing electron donor groups and doping alkali metal ions is a good candidate for well-performance NLO nanomaterial. [ABSTRACT FROM AUTHOR]