一种超支化共轭聚合物的合成与2,4-二硝基甲苯的荧光猝灭

Synthesis of a Fluorescent Hyperbranched Conjugated Polymer and Its Fluorescent Quenching to 2,4-Dinitrotoluene

以2,4,6-三甲基均三嗪和甲酰基咔唑、二甲酰基咔唑为原料,通过羟醛缩合反应合成了化合物I及超支化荧光共轭聚合物II,其中I可以视为II的组成单体。聚合物II在常见有机溶剂中有较好的溶解度,其X射线衍射谱图中2θ=24.2°的位置有1个较宽的峰;其吸收和荧光光谱与I的相比仅有轻微红移(3nm),这些结果都说明聚合物II分子间没有紧密的π-π堆积作用。聚合物II的荧光强度是化合物I的2倍。2,4-二硝基甲苯对其荧光猝灭研究结果表明,超支化聚合物II具有比化合物I更大的荧光猝灭常数(Ksv=95.52L/mol),表现出了一定的分子导线效应。

A hyperbranched polymer II and its monomer analogue I were synthesized from 2,4,6-trimethyl-s-triazine and formyl carbazolyl by aldole condensation reaction.Polymer II is easy soluble in common solvents.There is only one wide peak at 2θ = 24.2° in the XRD spectrum of II,indicating no close π-π aggregation between polymers.This hypothesis is in agreement with the fact that only small red-shift is found in the absorption and fluorescent spectra of II relative to those of I.Polymer II has higher fluorescent quantum yield(φf= 0.713) than I(φf= 0.382).Furthermore,Compared with I,polymer II exhibits larger Stern-Volmer constant(Ksv) in response to 2,4-dinitrotoluene(DNT),indicating fluorescence signal amplification occurs due to the molecular wire effect in the hyperbranched polymer II.