Synthesis of Silane-Based Poly(thioether) via Successive Click Reaction and Their Applications in Ion Detection and Cell Imaging

Allylsilane as a versatile handle in photoredox catalysis

Organosilanes have secured a special place in the synthetic world for several decades. However, among them, allylsilanes are a choice reagent for organic chemists to develop novel organic transformations. In recent years researchers have proved that visible-light photoredox catalysis has emerged as one of the most mild, sustainable, straightforward, and efficient strategies to construct simple to complex molecules with or without enantioselectivity. This review provides an in-depth analysis of recent advances and strategies employed in visible-light photoredox catalysis for allylsilane and its analogues for the development of various organic transformations. The review is divided into sections, each focused on a specific reactivity of allylsilane under light irradiation with C(sp2) center arene or alkene, C(sp2) center carbonyl, and C(sp3) center carbon functionality. In this review, we present optimization data, reaction scope, and mechanistic aspects to bring forward specific reactivity and selectivity trends of allylsilane in photoredox conditions.

Fluorescent Polymers Conspectus

The development of luminescent materials is critical to humankind. The Nobel Prizes awarded in 2008 and 2010 for research on the development of green fluorescent proteins and super-resolved fluorescence imaging are proof of this (2014). Fluorescent probes, smart polymer machines, fluorescent chemosensors, fluorescence molecular thermometers, fluorescent imaging, drug delivery carriers, and other applications make fluorescent polymers (FPs) exciting materials. Two major branches can be distinguished in the field: (1) macromolecules with fluorophores in their structure and (2) aggregation-induced emission (AIE) FPs. In the first, the polymer (which may be conjugated) contains a fluorophore, conferring photoluminescent properties to the final material, offering tunable structures, robust mechanical properties, and low detection limits in sensing applications when compared to small-molecule or inorganic luminescent materials. In the latter, AIE FPs use a novel mode of fluorescence dependent on the aggregation state. AIE FP intra- and intermolecular interactions confer synergistic effects, improving their properties and performance over small molecules aggregation-induced, emission-based fluorescent materials (AIEgens). Despite their outstanding advantages (over classic polymers) of high emission efficiency, signal amplification, good processability, and multiple functionalization, AIE polymers have received less attention. This review examines some of the most significant advances in the broad field of FPs over the last six years, concluding with a general outlook and discussion of future challenges to promote advancements in these promising materials that can serve as a springboard for future innovation in the field.

Improved enantioselectivity in thiol–ene photopolymerization of sulphur-containing polymers with circularly polarized luminescence

Optically active poly(thioether) are obtained based on CPL-triggered thiol–ene photopolymerization assisted with achiral HAD. The poly(thioether) exhibits clusterization-triggered emission and circularly polarized luminescence behavior.

A novel polythioether-based rhodamine B fluorescent probe via successive click reaction and its application in iron ion detection and cell imaging

Polythioether has good chemical stability and biocompatibility and is a kind of promising polymers for the application of optical materials, medical materials and energy conversion materials. However, the fluorescent probe based on polythioether is still rare. Herein, a series of polythioether based polymer fluorescent probes were synthesized by successive thiol click reaction under ultraviolet light at room temperature. The poly(thioether)s have good selectivity and responsiveness to iron ions and can be applied in cell imaging, which indicate that the broad application prospects of polythioether-based fluorescent probes in ion detection and bioimaging.