Efficient polymer photocatalysts that mimic natural photosynthesis to generate H 2 through the visible-light-promoted splitting of water are ideal systems for the conversion of solar energy into usable fuel with high energy density and in an environmentally friendly manner. In this article, we review recent reports on donor-acceptor-based π-conjugated polymers as photocatalysts, including conjugated linear polymers, microporous polymers, triazine frameworks, covalent organic frameworks, polymer dots, and other related organic polymers, which show superior photocatalytic activity and robust stability under visible-light irradiation, for hydrogen production. Moreover, their syntheses and material design strategies, photophysical properties, proposed mechanisms, and applications are systematically summarized. Finally, recent research on and challenges related to organic polymer photocatalysts are discussed. This minireview will help readers to more easily understand the recent advances in and future direction of this field.

Highly efficient thermally activated delayed fluorescence (TADF) molecules are in urgent demand for solid‐state lighting and full‐color displays. Here, the design and synthesis of three triarylamine‐pyridine‐carbonitrile‐based TADF compounds, TPAPPC, TPAmPPC, and tTPAmPPC, are shown. They exhibit excellent photoluminescence quantum yields of 79−100% with small ΔEST values, fast reverse intersystem crossing (RISC), and high horizontal dipole ratios (Θ// = 86−88%) in the thin films leading to the enhancement of device light outcoupling. Consequently, a green organic light‐emitting diode (OLED) based on TPAmPPC shows a high average external quantum efficiency of 38.8 ± 0.6%, a current efficiency of 130.1 ± 2.1 cd A–1, and a power efficiency of 136.3 ± 2.2 lm W–1. The highest device efficiency of 39.8% appears to be record‐breaking among TADF‐based OLEDs to date. In addition, the TPAmPPC‐based device shows superior operation lifetime and high‐temperature resistance. It is worth noting that the TPA‐PPC‐based materials have excellent optical properties and the potential for making them strong candidates for TADF practical application.

It's worth its salt: The title reaction leads to the synthesis of highly substituted isoquinolinium salts (see scheme; Cp*=Me5C5). The reaction proceeds through a CH activation and a subsequent annulation in the presence of a rhodium catalyst. The reaction mechanism is discussed as well as its application to the synthesis of the natural product oxychelerythrine.

An efficient and convenient method for the synthesis of highly substituted polycyclic pyridinium salts from the reaction of various 2-aryl-pyridines and 2-aryl-sp(2) -nitrogen-atom-containing heterocycles with alkynes through rhodium(III)-catalyzed CH activation and annulation under an O2 atmosphere is described. A possible mechanism that involves the chelation-assisted CH activation of the 2-aryl-pyridine substrate, insertion of the alkyne, and reductive elimination is proposed. This mechanism was supported by the isolation of a five-membered rhodacycle (I'). In addition, kinetic isotope studies were performed to understand the intimate reaction mechanism.

A new method for the synthesis of highly substituted naphthyridine-based polyheteroaromatic compounds in high yields proceeds through rhodium(III)-catalyzed multiple C-H bond cleavage and C-C and C-N bond formation in a one-pot process. Such highly substituted polyheteroaromatic compounds have attracted much attention because of their unique π-conjugation, which make them suitable materials for organic semiconductors and luminescent materials. Furthermore, a possible mechanism, which involves multiple chelation-assisted ortho C-H activation, alkyne insertion, and reductive elimination, is proposed for this transformation.