An intramolecular-locked strategy for designing nonlinear optical materials with remarkable first hyperpolarizability

To meet the expanding demands of high performance nonlinear optical (NLO) materials, an unprecedented intramolecular-locked strategy is proposed to design NLO materials with remarkable static first hyperpolarizability (beta(0)). This strategy means that importing a large steric hindrance group diphenylmethane (DPM) decreases the torsion angles (theta) between the donor {triphenylamine (TPA)} and acceptor {9-H-thioxanthen-9-one-10,10-dioxide (TXO)} units, as well as between the donor (TPA) and pi-bridge (benzene) fragments. The decrease of theta can accelerate the intramolecular charge transfer and enhance the contributions of the TPA, TXO and quinoxaline-6,7-dicarbo-nitrile (QCN) fragments to the axial component of the beta(0) value, and then the beta(0) values of TPA-TXO (beta(0) = 10 762 au) and TPA-QCN (beta(0) = 22 495 au) are increased by 14.9% and 34.4%, respectively. Overall, the intramolecular-locked strategy is very effective for designing high performance NLO materials.

Automated summary

An unprecedented intramolecular-locked strategy is proposed to design NLO materials with remarkable static first hyperpolarizability. This strategy involves the import of a large steric hindrance group to decrease torsion angles and enhance intramolecular charge transfer, resulting in improved performance of NLO materials.