This paper reports a new type of click chemistry via a phosphazene bases-catalyzed oxa-Michael addition of an alcohol to an acrylate.

The amide bond is one of the most pivotal functional groups in chemistry and biology. It is also the key component of proteins and widely present in synthetic materials. The majority of studies have focused on the formation of the amide group, but its postmodification has scarcely been investigated. Herein, we successfully develop the Michael additions of amide to acrylate, acrylamide, or propiolate in the presence of phosphazene base at room temperature. This amide Michael addition is much more efficient when the secondary amide instead of the primary amide is used under the same conditions. This reaction was applied to postfunctionalize poly(methyl acrylate-co-acrylamide), P(MA-co-Am), and it is shown that the amide groups of P(MA-co-Am) could be completely modified by N,N-dimethylacrylamide (DMA). Interestingly, the resulting copolymer exhibited tailorable fluorescence with emission wavelength ranging from 380 to 613 nm, which is a desired property for luminescent materials. Moreover, the emissions of the copolymer increased with increasing concentration in solution for all excitation wavelengths from 320 to 580 nm. Therefore, this work not only develops an efficient t-BuP 4 -catalyzed amide Michael addition but also offers a facile method for tunable multicolor photoluminescent polymers, which is expected to find a wide range of applications in many fields, such as in anticounterfeiting technology.

Here, a new type of anionic hybrid copolymerization is exploited via the concurrent oxa‐Michael addition of ethylene glycol and neopentyl glycol diacrylate and the ring‐opening polymerization of ε‐caprolactone. The hybrid copolymerization process and the resulting copolymers are characterized using nuclear magnetic resonance, size exclusion chromatography, differential scanning calorimetry measurements, and thermogravimetric analysis. The results show that the hybrid copolymerization can proceed smoothly under mild reaction conditions and that the synthesized copolymer contains ester and ether structures in the backbone, possibly endowing the polymers with good hydrophilicity and degradability. More importantly, the composition of the synthesized polymer can be easily adjusted by changing the monomer feed ratio, and the chain crystallization is significantly reduced due to the random copolymeric structure. This hybrid copolymerization reaction provides a new method for synthesizing degradable functional copolymers from commercially available materials. Hence, this polymerization is important not only in polymer chemistry but also in environmental and biomedical engineering.

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Development of a nonconjugated room temperature phosphorescence (RTP) system with a lifetime longer than 1 s remains a challenge. Here, we report a nonconjugated RTP polymer composed of amide-terminated hyperbranched polyether cross-linked with boric acid, whose phosphorescence lifetime can reach up to 2.40 s with a maximum absolute quantum yield of 26.5%. Moreover, their phosphorescent emission wavelength can be tuned from 517 to 585 nm by changing the excitation wavelength from 300 to 480 nm, while the afterglow color can be regulated from blue to yellow-red. Particularly, the nonconjugated RTP polymer exhibits a dual stimulus response to humidity and temperature, so it is expected to find applications in anticounterfeiting. The present study provides a strategy to design an RTP system with tunable emission and prolonged afterglow.