CO2-Involved and Isocyanide-based Three-component Polymerization toward Functional Heterocyclic Polymers with Self-assembly and Sensing Properties

CO<sub>2</sub> utilization has been a hot research topic in academic and industrial respects. Besides converting CO<sub>2</sub> into chemicals and fuels, incorporating it into the polymers to construct functional materials is another promising strategy. However, the CO<sub>2</sub>-involved polymerization techniques should be further developed. In this work, a facile and efficient CO<sub>2</sub>-involved multicomponent polymerization is successfully developed. The reaction of monomers of CO<sub>2</sub>, isocyanides and 2-iodoanilines readily produces soluble and thermally stable <a>poly(</a><a>benzoyleneurea</a>)s with well-defined structures under mild conditions. Thanks to the formed amide groups in the heterocyclic units in the main-chains, the resultant polymers <a>could self-assemble into </a>spheres with sizes between 200 and 1000 nm. <a>The polymers containing tetraphenylethylene (TPE) unit show the unique aggregation-enhanced emission (AEE) features, which could be used to visualize the self-assembly process and morphologies under UV irradiation</a><a>, and serve as fluorescence probe to selectively and sensitively detect Au<sup>3+</sup> ions. </a>Notably, the polymers<i> </i>containing<i> cis</i>- and <i>trans</i>-TPE units exhibit different behaviors in self-assembly and limit of detection for <a>Au<sup>3+</sup> ions</a> due to the different intermolecular interactions. Thus, this work not only provides a new strategy for CO<sub>2</sub> utilization but also furnishes a series of functional heterocyclic polymers for diverse applications.