title: Precision synthesis of poly(3-hexylthiophene) from catalyst-transfer Suzuki-Miyaura coupling polymerization.
abstract: (t)Bu(3) PPd(Ph)Br (1)-catalyzed Suzuki-Miyaura coupling polymerization of 2-(4-hexyl-5-iodo-2-thienyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2) was investigated. Monomer 2 was polymerized with 1 at 0 °C in the presence of CsF and 18-crown-6 in THF containing a small amount of water to yield P3HT with a narrow molecular weight distribution and almost perfect head-to-tail regioregularity. The M(n) values increased up to 11,400 g · mol(-1) in proportion to the feed ratio of 2 to 1. The MALDI-TOF mass spectra showed that P3HT with moderate molecular weight uniformly had a phenyl group at one end and a hydrogen atom at the other, indicating involvement of a catalyst-transfer mechanism. Successive 1-catalyzed polymerization of fluorene monomer 3 and then 2 yielded a well-defined block copolymer of polyfluorene and P3HT.
authors.affiliation: Department of Material and Life Chemistry, Kanagawa University, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan. yokozt01@kanagawa-u.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yokozawa
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Suzuki
authors.forename: Masataka
authors.initials: M
authors.lastname: Nojima
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ohta
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yokoyama
mesh_terms: D002384:Catalysis; D043844:Crown Ethers / Q000737:chemistry; D003516:Cycloparaffins / Q000138:chemical synthesis; D005449:Fluorenes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D009942:Organometallic Compounds / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013876:Thiophenes / Q000138:chemical synthesis*; D014867:Water / Q000737:chemistry
chemical_list: D043844:Crown Ethers; D003516:Cycloparaffins; D005449:Fluorenes; D009942:Organometallic Compounds; D011108:Polymers; D013876:Thiophenes; C507295:poly(3-hexylthiophene); C509547:poly-para-phenylene; D014867:Water; D010165:Palladium; C015762:18-crown-6; D006859:Hydrogen