title: Transition-Metal-Free Synthesis of 1,3-Butadiene-Containing π-Conjugated Polymers.
abstract: This work describes the synthesis of π-conjugated polymers possessing arylene and 1,3-butadiene alternating units in the main chain by the reaction of α,β-unsaturated ester/nitrile containing γ-H with aromatic/heteroaromatic aldehyde compound. By using 4-(4-formylphenyl)-2-butylene acid ethyl ester as a model monomer, the different polymerization conditions, including catalyst, catalyst amount, and solvent, are optimized. The polymerization of 4-(4-formylphenyl)-2-butylene acid ethyl ester is carried out by refluxing in ethanol for 72 h with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst to give a 1,3-butadiene-containing π-conjugated polymer, poly(phenylene-1,3-butadiene), in 84.3% yield with M¯n and M¯w/M¯n (PDI) estimated as 6172 and 1.65, respectively. Based on this new methodology, a series of π-conjugated polymers containing 1,3-butadiene units with different substituents are obtained in high yields. A possible mechanism is proposed for the polymerization through a six-membered ring transition state and then a 1,5-H shift intermediate.
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Xuediao
authors.initials: X
authors.lastname: Cai
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Lu
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Chuxin
authors.initials: C
authors.lastname: Luo
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Chai
mesh_terms: D002070:Butadienes / Q000737:chemistry*; D002384:Catalysis; D000431:Ethanol / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D002070:Butadienes; D011108:Polymers; D000431:Ethanol; C031763:1,3-butadiene
keywords: green solvents; organic base catalysts; poly(arylene-1,3-butadiene)s; transition-metal-free catalysts; π-conjugated polymers