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Research of thermally activated delayed fluorescence (TADF) and room‐temperature phosphorescence (RTP) materials is attractive owing to their extensive applications in various fields. However, achieving organic TADF and RTP materials, particularly those with stimulus‐responsiveness and tunability, is highly desirable but challenging and rarely reported. Herein, two easily synthesized organic molecules are reported with abnormal stimulus‐responsive switchable TADF and RTP effects, in which phenothiazine (PTZ) and benzo[b]phenothiazine (BPTZ) based donor−acceptor molecules PTZ‐DBQ and BPTZ‐DBQ show mechanical‐induced TADF in crystalline phase and photo‐responsive RTP in doping poly(methyl methacrylate) (PMMA) films. This is the first time tetracyclic BPTZ has been used as a donor in achieving TADF and RTP materials, and it is found that BPTZ‐DBQ exhibits remarkably better photophysical properties than PTZ‐DBQ. Systematic studies of experimental results and theoretical calculations indicate that the conformational heterogeneity plays an essential role in achieving mechanical‐induced TADF with mechanochromic luminescence (MCL) property. Embedding the organic phosphors into rigid polymer matrices effectively suppresses the molecular motion, thus turning on the RTP emission channel. The conversion of 3O2 to 1O2 under UV irradiation is mainly responsible for the photo‐induced process. These multifunctional luminescent materials have great potential applications in chemical sensors, information encryption, and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Concise and scalable formal syntheses of (-)-quinocarcinamide and (-)-quinocarcin have been achieved in 9 steps with 9% overall yield from simple commercially available chemicals. The synthetic strategy features an ortho -regioselective Pictet-Spengler cyclization for the construction of the tetrahydroisoquinoline skeleton, a stereoselective formal intramolecular [3 + 2] cross cycloaddition of cyclopropane 1,1-diester with an imine for the construction of the 3,8-diazabicyclo[3.2.1]octane skeleton.

In this paper, a 53 Gbps widely tunable transmitter is experimentally demonstrated for the first time, to our knowledge. An InGaAlAs/InP multiple-quantum-well (MQW) wafer is used with an identical layer structure for both the V-coupled cavity laser (VCL) and the electro-absorption modulator (EAM). The VCL uses a shallow-etched waveguide to reduce loss, while the EAM uses a deep-etched waveguide to increase the 3-dB modulation bandwidth. With the temperature varying from 19.5 to 30°C, the transmitter achieves wavelength tuning of 42 channels with a spacing of 100 GHz, corresponding to a tuning range of 32.6 nm from 1538.94 to 1571.54 nm. The static extinction ratio (ER) for all channels is higher than 14 dB. The measured 3-dB electro-optic (E0) bandwidth of the transmitter is over 40 GHz, which fits well with the calculated 3-dB bandwidth. At a fixed peak-to-peak driving voltage of 2.4 V, all channels exhibit clearly an open eye diagram with a 53 Gbps non-return-to-zero (NRZ) signal, while the dynamic ER is higher than 4.5 dB.