Synthesis Of Functional Poly(phenyltriazolylcarboxylate)s By Metal-free Polymerization Of Phenylpropiolates And Azides

The cycloaddition of terminal alkynes and azides to prepare triazoles has been developed into an efficient polymerization reaction,which has been widely used in the synthesis of functional polytriazoles.However,the polycycloadditions of internal alkynes and azides have been rarely reported.In this work,we have developed a new metal-free phenylpropiolate-azide polycycloaddition reaction,and synthesized a series of functional poly(phenyltriazolylcarboxylate)s(PPTCs)with linear and hyperbranched structures.The thermally initiated polymerization reaction of diazide and 4,4’-isopropylidenediphenyl diphenylpropiolate was firstly explored.The effects of temperature,monomer concentration,reaction time and solvent on the molecular weights,yields and regioregularities of the polymers were systematically investigated.The optimal polymerization reaction conditions were obtained.Furthermore,the polymerization is insentive to oxygen and moisture,and can be performed in an open atmosphere.We then prepared seven linear PPTCs with high molecular weights and regioregularities.The resultant polymers could be degraded in the prensence of KOH aqueous solution.The tetraphenylethene(TPE)-containing PPTCs exhibiting aggragation-induced emission(AIE)characteristics can serve as fluorescent chemosensors for explosive detection.Five soluble hyperbranched PPTCs with high molecular weights were prepared by the polycycloadditions of triphenylpropiolates and diazides through optimizing the polymerization conditions.The TPE-containing PPTCs could generate two-dimensional fluorescent patterns,and used as fluorescent chemosensors for explosive detection.Four soluble ferrocene-containing hyperbranched PPTCs with high molecular weights were synthesized by the polycycloadditions of triphenylpropiolates and ferrocene-containing diazides.The resulting polymers showed electrochemical activity and could be used as precursors to yield nanostructured magnetic ceramics.