A series of novel persistent room-temperature phosphorescence (pRTP) materials (PEPCz) obtained via a combination of chalcogen atoms (O, S, Se, and Te) and a carbazolyl moiety is reported. Single crystal structure analysis revealed that PEPCz had similar molecular conformations and almost identical crystal packing. Mechanistic study showed that the intramolecular electronic coupling between the chalcogen atoms and π-units was responsible for tunable pRTP. The PEPCz were used not only to realize graphic encryption, but also to fabricate pRTP sensors for H2O2 and TNT detection.

A series of novel ortho-terphenylene viologen derivatives (o-TPV 2+ ) with through-space conjugation (TSC) via the combination of ortho-terphenylene skeletons with viologen structure is reported. Their optoelectronic properties can be adjusted by N-arylation or N-alkylation reactions. Compared with other viologen derivatives, o-TPV 2+ not only exhibits strong photoluminescence but also retards the charge recombination process and stabilizes the diradical state without forming a quinoid structure due to the special TSC effect. Based on their special redox characteristics, o-TPV 2+ was applied to the photocatalytic oxidative coupling of benzylamine with 96% yield. In addition, pTA-o-TPV 2+ (tethered with p-toluic acid)-modified g-C 3 N 4 was used for visiblelight-driven hydrogen production for the first time, exceeding 15 times the rate over unmodified g-C 3 N 4 .

Although naphthalene diimide (NDI) and its derivatives have been widely used for organic Li-ion batteries (OLIBs), they are limited by a low lithium uptake capacity and ambiguous lithiation mechanism. Herein, we report two isometric thionated-NDI cathodes (cis-2S and trans-2S) obtained by replacing O with S in the imide groups which improves the battery performance compared with parent NDI (P-NDI). Remarkably, the position of S atoms plays an important role as the potential plateau of cis-2S was 100 mV higher than trans-2S, 256 mV higher than P-NDI, and the capacity of cis-2S was twice than that of trans-2S, four times as P-NDI after 400 cycles. The in situ Raman, X-ray photoelectron spectroscopy (XPS), and DFT calculations revealed that the lithiation process occurs on the less electronegative S atoms. For cis-2S, the electron density on the lithiation sites is lower than trans-2S because of a stronger electron inductive effect. This in turn enhances the redox potential and cycling stability of cis-2S. This contribution provides an additional molecular engineering strategy to develop novel organic cathode materials for high performance OLIBs.