We introduce a fluorescence‐based methodology enabling the quantification of ligation points in photochemically prepared polymer networks. Well‐defined α,ω‐tetrazole‐capped polymer strands prepared via RAFT polymerization are crosslinked under UV irradiation by a trimaleimide via nitrile imine mediated tetrazole–ene cycloaddition. Thus, for each linkage point a fluorescent pyrazoline ring is formed, resulting in fluorescent networks, which are degradable by aminolysis of the trithiocarbonate functionalities, leading to soluble fragments. The fluorescence emission of the soluble network fragments correlates directly with the number of pyrazoline moieties originally present in the network, thus providing a direct measure of the number of ligation points constituting the network. The herein introduced strategy based on a fluorescence readout is a powerful yet simple approach to quantify network formation processes applicable to a wide class of polymers accessible via RAFT.

中文翻译：

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计算荧光聚合物网络中的点击次数

我们引入了一种基于荧光的方法，可以对光化学制备的聚合物网络中的连接点进行定量。通过RAFT聚合制备的定义明确的α，ω-四唑封端的聚合物链在三甲基亚胺的紫外线辐射下，通过腈亚胺介导的四唑-烯环加成反应交联。因此，对于每个连接点，形成荧光吡唑啉环，产生荧光网络，该荧光网络可通过三硫代碳酸酯官能团的氨解而降解，从而产生可溶性片段。可溶性网络片段的荧光发射与网络中最初存在的吡唑啉部分的数量直接相关，因此可以直接测量构成网络的连接点的数量。