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Four new Y-shaped NIR fluorophores are rationally designed and concisely synthesized; of these, 3b is developed as a practical fluorescent probe for PA.

Metal-free catalyzed intermolecular tandem Michael addition/cyclization is developed for the synthesis of benzo[4,5]imidazo[1,2-a]pyridines from α-bromocinnamaldehyde. The RIM of the benzene ring at the C1-position makes them a new class of AIE molecules.

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Summary A series of N -alkyl-substituted polybenzimidazoles ( SPBIs ), synthesized by simple condensation and N -alkylation, act as functional materials with tunable microstructures and sensing performance. For their controllable morphologies, the formation of nano-/microspheres is observed at the n (RBr)/ n (PBI) feed ratio of 5:1. Products with different degrees of alkylation can recognize metal ions and nitroaromatic compounds (NACs). For example, SPBI-c , obtained at the feed ratio of 1:1, can selectively detect Cu 2+ , Fe 3+ , and NACs. By contrast, SPBI-a , obtained at the feed ratio of 0.1:1, can exclusively detect Cu 2+ with high sensitivity. Their sensing mechanisms have been studied by FT-IR spectroscopy, SEM, XPS, and DFT calculations. Interestingly, the SPBIs can adsorb Cu 2+ in solution and show good recyclability. These results demonstrate that polymeric materials with both sensing and adsorption applications can be realized by regulating the alkylation extent of the main chain, thus providing a new approach for the facile synthesis of multifunctional materials.

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Summary The bio-based lactic acid (LA) and the common metal ion chelating agent iminodiacetic acid (IDA) are used to design and prepare a polymeric sustained-release Pb 2+ chelating agent by a brief one-step reaction. After the analysis on theoretical calculation for this reaction, poly(lactic acid-iminodiacetic acid) [P(LA- co -IDA)] with different monomer molar feed ratios is synthesized via direct melt polycondensation. P(LA- co -IDA) mainly has star-shaped structure, and some of them have two-core or three-core structure. Thus, a possible mechanism of the polymerization is proposed. The degradation rate of P(LA- co -IDA)s can reach 70% in 4 weeks. The change of IDA release rate is consistent with the trend of the degradation rate, and the good Pb 2+ chelating performance is confirmed. P(LA- co -IDA) is expected to be developed as a lead poisoning treatment drug or Pb 2+ adsorbent in the environment with long-lasting effect, and this research provides a new strategy for the development of such drugs.

Organic fluorescent polymers have unique characteristics of fluorescent signal amplification and good optical properties, and can detect specific analytical species. Their sensing performance can be further improved through reasonable modification of their side chains. Nowadays, the organic fluorescent polymers are mainly prepared by metal coupling reactions, and there are also some syntheses involving in addition polymerization and condensation reactions. Taking the fluorescent source of these polymers as the main line, the research progress of the fluorescent organic polymers in the sensor field in recent years is systematically reviewed from the perspective of the type of reaction, especially their design and synthesis, sensing application, detection mechanism are summarized. In the future, it is still to be further investigated to design and synthesize novel multifunctional organic polymer fluorescence sensors as the key development direction.