This review summarizes the recent advancements in π-conjugated polymers for various photocatalytic applications under visible light.

The development of new means of activating molecules and bonds for chemical reactions is a fundamental objective for chemists. In this regard, visible-light photoredox catalysis has emerged as a powerful technique for chemoselective activation of chemical bonds under mild reaction conditions. Here, we report a visible-light-mediated photocatalytic alcohol activation, which we use to convert alcohols to the corresponding bromides and iodides in good yields, with exceptional functional group tolerance. In this fundamentally useful reaction, the design and operation of the process is simple, the reaction is highly efficient, and the formation of stoichiometric waste products is minimized.

Three dibenzothiophene-S,S-dioxide-based alternating copolymers were synthesized by facile Suzuki polymerization for visible light-responsive hydrogen production from water (> 420 nm). Without addition of any cocatalyst, FluPh2-SO showed a photocatalytic efficiency of 3.48 mmol h g- , while a larger hydrogen evolution rate (HER) of 4.74 mmol h g was achieved for Py-SO, which was ascribed to the improved coplanarity of the polymer that facilitated both intermolecular packing and charge transport. To minimize the possible steric hindrance of FluPh2-SO by replacing 9,9'-diphenylfluorene with fluorene, Flu-SO exhibited a more red-shifted absorption than FluPh2-SO and yielded the highest HER of 5.04 mmol h g . This work highlights the potential of dibenzothiophene-S,S-dioxide as a versatile building block and the rational design strategy for achieving high photocatalytic efficiency.

Friedel-Crafts amidoalkylation was achieved by oxidation of dialkylamides using persulfate (S2O82−) in the presence of the visible light catalyst, Ru(bpy)3Cl2, at room temperature, via a reactive N-acyliminium intermediate. Alternatively, mild heating of the dialkylamides and persulfate afforded a metal and Lewis acid-free Friedel-Crafts amidoalkylation. Alcohols and electron–rich arenes served as effective nucleophiles, forming new C–O or C–C bonds. In general, photocatalysis provided higher yields and better selectivities.

As a demonstration of an alternative to the challenges faced with batch pharmaceutical manufacturing including the large production footprint and lengthy time-scale, we previously reported a refrigerator-sized continuous flow system for the on-demand production of essential medicines. Building on this technology, herein we report a second-generation, reconfigurable and 25 % smaller (by volume) continuous flow pharmaceutical manufacturing platform featuring advances in reaction and purification equipment. Consisting of two compact [0.7 (L)×0.5 (D)×1.3 m (H)] stand-alone units for synthesis and purification/formulation processes, the capabilities of this automated system are demonstrated with the synthesis of nicardipine hydrochloride and the production of concentrated liquid doses of ciprofloxacin hydrochloride, neostigmine methylsulfate and rufinamide that meet US Pharmacopeia standards.

A novel D-A conjugated polymer backbone containing silole and 9-octyl-9H-carbazole units was synthesized via Sonogashira reaction. This silole-containing polymer (SCP) was further used to prepare SCP dots with a nanoprecipitation method, which showed an electrochemiluminescence (ECL) emission at relatively low potential in aqueous solution. The strong anodic ECL emission could be observed at +0.4 V (vs Ag/AgCl) with a peak value at +0.78 V in the presence of tri-n-propylamine (TPrA) as a co-reactant, which came from the band gap emission of the excited SCP dots. The ECL emission could be quenched via resonance energy transfer from the excited SCP dots to an acceptor. Thus, a low-potential anodic ECL sensing strategy was proposed for ECL detection of the acceptor-related analytes. Using dopamine as the analyte, whose electro-oxidation product could act as the energy acceptor to quench the ECL emission of SCP dots, the ECL detection method showed a detection limit of 50 nM and high anti-interference ability. This work demonstrates an example of polymer dots as an ECL emitter and its potential application in ECL detection methodology.

Cleavage of carbon–halogen bonds via either single-electron reduction or atom transfer is a powerful transformation in the construction of complex molecules. In particular, mild, selective hydrodehalogenations provide an excellent follow-up to the application of halogen atoms as directing groups or the utilization of atom transfer radical addition (ATRA) chemistry for the production of hydrocarbons. Here we combine the mechanistic properties of photoredox catalysis and silane-mediated atom transfer chemistry to accomplish the hydrodebromination of carbon–bromide bonds. The resulting method is performed under visible light irradiation in an open vessel and is capable of the efficient reduction of a variety of unactivated alkyl and aryl substrates.

Two AIE-active chiral BINOL-based O-BODIPY enantiomers (R/S-5) were synthesized and showed mirror-image red-color CPL induced via intramolecular energy transfer. The chiroptical properties of the molecules indicate that the chirality of electronic ground and excited states is stable and independent of aggregation.