The nonlinear optical properties of acyclic triarylamine-conjugated dimethyl diethynylfumarate and its two cyclic Pechmann dyes derivatives: A theoretical study

摘要

DFT and TDDFT calculations were used to investigate the potential use of two Pechmann dyes as efficient nonlinear optical (NLO) compounds. The two Pechmann dyes are with cyclic cores formed by acid-induced double lactonization from their parent acyclic core compound dimethyl 2,3-bis((4-(bis(4-methoxyphenyeamino)phenyeethynyefumarate (parent compound; El). The two Pechmann dyes are (E)-5,5'-bis(4-(bis(4-methoxyphenyeamino)pheny1)-2H,2'H-[3,3' bifuranylidene]-2,2'-dione (P55), and 3,7-bis(4-(bis(4-methoxyphenyl)amino)phenyl)pyrano [4,3-c] pyran-1,5-dione (P66). The polarizability parameters were calculated and analyzed. To rationalize the NLO response, the following parameters were calculated and discussed: (1) the charge transfer descriptors, (2) the linear optical properties, (3) Fukui indices, and (4) the two-level model. According to the calculated parameters, the better performance of P66 as NLO material was ascribed to the improved intramolecular charge transfer (IACT) properties of this molecule.