Spatiotemporally Controlled Light‐Induced Click Polymerization of Activated Alkyne With 2‐Methylbenzaldehydes for Patterning and Bioimaging Applications

Although alkyne‐based polymerizations have significant potential for advanced materials, achieving efficient and spatiotemporally controlled polymerizations under mild, additive‐free conditions remains a challenge. In this work, we report a facile light‐induced click polymerization between activated alkynes and 2‐methylbenzaldehydes ( o ‐MBAS). This polymerization can be completed within 1 h at room temperature without any catalysts or additives, and features high atom economy, spatiotemporal controllability, and operational simplicity. Under optimized conditions, a series of soluble and thermally stable poly(naphthalene)s, poly(anthracene), and poly(phenanthrene) with high molecular weights ( M w up to 46,800 Da) were obtained in excellent yields (up to 99%). The resulting polymers exhibit outstanding photophysical properties. The poly(anthracene) can specifically label lipid droplets in cells. In addition, introducing the tetraphenylethylene (TPE) moiety into the polymer backbones endows the resultant polymers with unique aggregation‐induced emission (AIE) properties, enabling the preparation of fluorescent patterns. Moreover, the precise spatiotemporal nature of this polymerization also supports the fabrication of well‐defined 2D and 3D polymer architectures. This work not only expands the scope of alkyne‐based polymerizations but also provides a useful and flexible platform for the spatiotemporally controlled synthesis of polymers.