Remarkable nonlinear optical response of pyrazine-fused trichalcogenasumanenes and their application for optical power limiting†
The C3v-symmetric hetera buckybowl trichalcogenasumanenes have attracted recent interest due to their unique features in chemical and optoelectronic aspects. To gain a nonlinear optical (NLO) response, the electron-withdrawing unit pyrazine was introduced onto tricalcogenasumanenes to give the pyrazine-fused trithiasumanene (1) and triselenasumanene (2) as reported herein. Compounds 1 and 2 exhibit typical NLO properties which are verified using open-aperture Z-scan technology under a 532 nm nanosecond laser pulse. It is found that the NLO performance of these two molecules is much better than the state-of-the-art NLO material C60. The time-resolved transient absorption clearly verified that the NLO properties of 1 and 2 originate from the reverse saturable absorption (RSA) of the triplet excited-state. Owing to their remarkable NLO performance, 1 and 2 are further employed as optical power limiting (OPL) materials. Compounds 1 and 2 exhibit OPL behavior with a limiting threshold of 1.78 J cm−2 and 2.43 J cm−2, respectively; this performance is better than that of C60 (12.85 J cm−2). This work indicates that the sumanene derivatives are promising candidates for NLO and OPL materials.
- This article is part of the themed collection: 2018 Journal of Materials Chemistry C HOT Papers