Design And Preparation Of Novel Substituted Acetylene Polymers And Construction Of Chiral Luminescent Materials

The design and development of polymer functional materials have great application potential in the fields of polymer chemistry,materials science and supramolecular science,which has attracted extensive attention of researchers.For acetylene polymers,the most extensive studies can be divided into two categories.One is the research of click polymerization of acetylene monomer with bifunctional or multifunctional groups.The other is the preparation of helical substituted polyalkynes and their research in chiral luminescence properties.Alkyne click polymerization conforms to the research concept of green chemistry.As a method for preparing functional polymer materials,it has many advantages,such as mild reaction conditions,high reaction efficiency,high atomic utilization efficiency,and so on.The construction of novel catalyst-free reaction systems has always been a hot topic in this field.Helical substituted polyalkynes are well known for their dynamic helical structure,chiral amplification effect and circularly polarized luminescence（CPL）properties.In addition,CPL materials have become a new research hotspot in the field of photoelectric functional materials due to their great application potential in the fields of organic light emitting devices,data storage and processing,3D display,and other fields.However,the improvement of the luminescence asymmetry factor of CPL materials,the control of CPL performance,and the preparation of full-color and white CPL materials are still the focus and difficulty of research in this field.In this thesis,we have designed and prepared several new types of alkyne monomers,constructed functional polymer materials using click polymerization and coordination polymerization methods respectively,and explore their performance and application prospects.The specific research contents are as follows:1.We designed and synthesized a new di-terminal alkynyl monomer containing benzene ring and amide structure,and successfully realized the click polymerization reaction of thiol and alkyne monomer under catalyst-free conditions.The monomer reacts with aliphatic mercaptans to obtain oligomers,but reacts with aromatic mercaptans to obtain polymers with a relatively high molecular weight in a high yield.In addition,the obtained products have high stereoselectivity.Due to the existence of benzene ring,the prepared polymers have good thermal stability.2.Chiral Schiff base alkyne monomers and non-chiral fluorescent alkyne monomers containing dansyl group were synthesized.A series of chiral helical copolymers with different copolymerization ratios were prepared using these two alkyne monomers.CPL emission was not obtained due to the unsuccessful transfer of chirality to the fluorescent group in the copolymer.However,the Schiff base copolymer R-P19 showed good performance for ion detection of Cr³⁺,with good fluorescence enhancement effect as well as anti-interference ability.The detection limit of polymer R-P19 for Cr³⁺was 1.9×10^-6 mmol/m L.This provides a new research idea and direction for the detection of Cr³⁺in solution.3.Chiral film materials with strong optical activity have been prepared using chiral induction strategies based on non-chiral helical polymers,in which intermolecularπ-πstacking effects are found to be the main driving force for chiral induction.The full-color and white CPL materials were successfully prepared by introducing fluorescent components.In addition,we have established a novel CPL generation mechanism,circularly polarized light excitation（CP-Ex）.The amplification of luminescence dissymmetry factor was achieved under the synergetic effect of circularly polarized light excitation（CP-Ex）and chirality transfer in chiral fluorescent blend films.Double-layered system composed of chiral layer and fluorescent layer was constructed to further verify CP-Ex mechanism,and switchable CPL emissions were accomplished by changing the direction of excitation light.This may open up a new platform for preparing CPL active materials.