Vinyl acetate is polymerized in the living way under the irradiation of blue light-emitting diodes (LEDs) or sunlight without photocatalyst at ambient temperature. 2-(Ethoxycarbonothioyl)sulfanyl propanoate is exclusively added and acts as initiator and chain transfer agent simultaneously in the current system. Poly(vinyl acetate) with well-regulated molecular weight and narrow molecular weight distribution (Đ < 1.30) is synthesized. Near quantitative end group fidelity of polymer is demonstrated by nuclear magnetic resonance (NMR) and matrix-assisteed laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

The radical polymerization of styrene was investigated in the presence of five diaryl diselenide compounds with different substitution groups on the benzene ring under visible light irradiation. It showed that bis-(2,6-dimethylphenyl) diselenide (DmXDS) with two methyl groups on every benzene ring was the most efficient mediator for preparing polymers with a predetermined molecular weight and narrow molecular weight distribution. The reasons were analyzed through a quantum calculation method. The polymerization behavior of styrene in the presence of DmXDS was further investigated in depth. The results showed a typical living radical polymerization process. Polymers retaining the selenide structures at both the αand ω-ends were verified by NMR and MALDI-TOF. Such end capped selenide groups could be transformed into terminal vinyl groups with a high efficiency under oxidative conditions, which offers a route to prepare "macromonomers" with a narrow molecular weight distribution. † Electronic supplementary information (ESI) available: The NMR spectra and UV-vis spectra of the diaryl diselenides, GPC curves of the polymers, and calculation results. See

Diselenide-containing polymers are facilely synthesized from polymers prepared by atom transfer radical polymerization (ATRP). Benefiting from the ATRP technology, this protocol provides a flexible route for controlling the polymer structure, which allows for a great variety of architectures of selenium-containing polymer materials for applications in various fields. The oxidative and reductive responsive behavior of the obtained diselenide-containing polymers is also investigated.

A simple and versatile method for preparing selenide-containing polymers with desired topologies is established based on the reaction of a selenide-functionalized borohydride exchange resin with end-functionalized polymers.