Alkyne-Based Polymerization Towards Conjugated Polymer

The development of new polymerization methodologies for the construction of?-conjugated polymers with unique photoelectronic properties is of great importance.Multicomponent tandem polymerizations?MCTPs?which are recently designed for conjugated polymer synthesis,are featured with high synthetic efficiency and convenience.Alkynes are frequently used as building blocks for the construction of conjugated or heterocyclic-containing polymers.Till now,the reported multicomponent polymerizations of alkyne are rarely used in the synthesis of conjugated polymer.In this thesis,we mainly focus on the development of new alkyne-based polymerization methodologies for the construction of conjugated polymers.A new multicomponent tandem polymerization was developed for the efficient and convenient synthesis of conjugated poly?pyrimidines?with well-defined structure,high molecular weight,and high yield,through the combination of Hay-Glaser coupling reaction of diyne monomer and the following addition-heterocyclization-oxidation reactions of accumulated diyne,guanidine,DMSO,and oxygen in a one-pot reaction in a sequential manner.The MCTP features high efficiency,which can convert simple monomers to complex heterocycle-containing products in a step-economic manner.It also constructs new functional units in situ which is difficult to realize by other synthetic methods.Moreover,the polymer mainchain structure can be switched from conjugated backbone to non-conjugated backbone by simply changing the reaction atmosphere from air to nitrogen,demonstrating high convenience and reliability of structural control.The kinetic study of the polymerization by in situ IR spectra proves the fast speed of the polymerization,indicating that the solvent molecule DMSO is also participated in the reaction,which is confirmed by the deuterated DMSO-involved reactions.The poly?pyrimidines?enjoy outstanding thermal resistance with high decomposition temperature and high carbonized residual.Moreover,the subtle difference in the polymer structure endows them different hydrophilic and photophysical properties.With the unique functional groups of these poly?pyrimidines?such as amino groups,pyrimidine groups,and potential multiple hydrogen bonds,it is anticipated that these polymer materials can found various applications in self-assembly and self-healing,metal-chelation,and fluorescence sensors.We further developed a new polymerization based on the reaction of perfluoroalkyl iodides and alkynes for the synthesis of perfluoroalkylated enynes.The reaction proceeds through the addition of iodoperfluoroalkanes to terminal alkynes and subsequent Sonogashira coupling with another molecule of alkyne.The polymer was obtained in high yield?89%?with satisfactory weight-average molecular weight of 60 500 g/mol under optimized polymerization conditions.Through the comparison of the FTIR spectra,¹H NMR spectra,¹³C NMR spectra,and ¹⁹F NMR spectra of the monomer,model compound and polymer,the expected chemical structure of the obtained polymers are proved.All the polymers process good solubility and outstanding thermal resistance.