Frequency-upconverted Stimulated Emission by Up to Six-photon Excitation from Highly Extended Spiro-fused Ladder-type Oligo(p-phenylene)s.

Frequency-upconverted Stimulated Emission by Up to Six-photon Excitation from Highly Extended Spiro-fused Ladder-type Oligo(p-phenylene)s.
Angew Chem Int Ed Engl. 2021 Jan 21;:
Authors: Jiang Y, Li KF, Gao K, Lin H, Tam HL, Liu YY, Shu Y, Wong KL, Lai WY, Cheah KW, Huang W
Abstract
The frequency-upconverted fluorescence and stimulated emission induced by multi-photon absorption (MPA) have attracted much interest. As compared with low-order MPA process, the construction of high-order MPA process is highly desirable and rather attractive, yet remains a formidable challenge due to its inherent low transition probability. Herein, we report the observation of the first experimental frequency-upconverted fluorescence and stimulated emission by simultaneous six-photon excitation in organic molecular system. The well designed organic conjugated system based on cross-shaped spiro-fused ladder-type oligo(p-phenylene)s (SpL-z, z=1-3) manifests quite high MPA cross-sections and brilliant luminescence emission simultaneously. The six-photon absorption cross-section of SpL-3 with an extended π-conjugation was evaluated as 8.67 × 10-169 cm12 s5 photon-5. Exceptionally efficient 2- to 6-photon excited stimulated emission have been achieved under near-infrared laser excitation.
PMID: 33476095 [PubMed - as supplied by publisher]

Source: Angewandte Chemie - January 21, 2021 Category: Chemistry Authors: Jiang Y, Li KF, Gao K, Lin H, Tam HL, Liu YY, Shu Y, Wong KL, Lai WY, Cheah KW, Huang W Tags: Angew Chem Int Ed Engl Source Type: research