Theoretical study on the one‐, two‐, and three‐photon absorption properties of exohedral functionalized derivative of Sc₃N@C₈₀

Abstract

Geometrical structures of three investigated molecules Sc 3 N@C 80 , Sc 3 N@C 80 -Fc, and C 60 -Fc were optimized by density functional theory (DFT) at the B3LYP/6-31G* level. Then the time-dependent DFT was employed to investigate the excited states of these molecules. After exohedral functionalization by ferrocene (Fc-) group as the electron donor or replacing C 60 with Sc 3 N@C 80 as the electron acceptor, the wavelengths of the first one-photon absorption peak and the strongest two-photon absorption (2PA) and three-photon absorption (3PA) peaks shift red. The corresponding cross sections of Sc 3 N@C 80 -Fc in the 2PA and 3PA processes increase as compared with those of Sc 3 N@C 80 , which originate from the contributions of charge transfers from Fc-group to C 80 cage and simultaneously the transfers from the C 80 cage to the encapsulated Sc 3 N cluster. When compared with C 60 -Fc, the 2PA and 3PA cross sections of Sc 3 N@C 80 -Fc decrease, which may result from the more negative charge surface of C 80 cage in Sc 3 N@C 80 -Fc molecule which blocks the charge transfers from Fc-moiety to the C 80 cage in the excitation processes by compared with C 60 -Fc.