Next Article in Journal
Emerging Applications of Liquid Crystals Based on Nanotechnology
Next Article in Special Issue
Selective Interaction of a Cationic Polyfluorene with Model Lipid Membranes: Anionic versus Zwitterionic Lipids
Previous Article in Journal
Formation of Nanocones on Highly Oriented Pyrolytic Graphite by Oxygen Plasma
Previous Article in Special Issue
Electrospun Polymer Fibers for Electronic Applications
Open AccessArticle

Preparation and Chemical Properties of π-Conjugated Polymers Containing Indigo Unit in the Main Chain

College of Biomolecular Functional Engineering, Faculty of Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi 316-8511, Japan
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
Institute of Advanced Energy, Kyoto University, Gokasyo, Uji 611-0011, Japan
Authors to whom correspondence should be addressed.
Materials 2014, 7(3), 2030-2043;
Received: 19 January 2014 / Revised: 21 February 2014 / Accepted: 26 February 2014 / Published: 11 March 2014
(This article belongs to the Special Issue Conjugated Polymers)
π-Conjugated polymers based on indigo unit were prepared. Dehalogenative polycondensation of N-hexyl-6,6'-dibromoindigo with a zerovalent nickel complex gave a homopolymer, P(HexI), in 77% yield. Copolymer of N-hexyl-indigo and pyridine, P(HexI-Py), was also prepared in 50% yield. P(HexI) showed good solubility in organic solvents, whereas P(HexI-Py) was only soluble in acids such as HCOOH. The weight-average molecular weights (Mw) of P(HexI) and P(HexI-Py) were determined to be 10,000 and 40,000, respectively, by a light scattering method. Pd-catalyzed polycondensation between 6,6'-dibromoindigo with N-BOC (BOC = t-butoxycarbonyl) substituents and a diboronic compound of 9,9-dioctylfluorene afforded the corresponding alternating copolymer, P(BOCI-Flu), as a deep red solid in 98% yield. P(BOCI-Flu) was soluble in N-methyl-2-pyrroridone and showed an Mw of 29,000 in GPC analysis. Treatment of P(BOCI-Flu) with CF3COOH smoothly led to a BOC-deprotection reaction to give an insoluble deep green polymer, P(I-Flu), in a quantitative yield. Diffuse reflectance spectra of powdery P(BOCI-Flu) and P(I-Flu) showed peaks at about 580 nm and 630 nm, respectively, which are thought to originate from the indigo unit. View Full-Text
Keywords: π-conjugated polymer; indigo; polycondensation; H-chromophore π-conjugated polymer; indigo; polycondensation; H-chromophore
MDPI and ACS Style

Fukumoto, H.; Nakajima, H.; Kojima, T.; Yamamoto, T. Preparation and Chemical Properties of π-Conjugated Polymers Containing Indigo Unit in the Main Chain. Materials 2014, 7, 2030-2043.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

Only visits after 24 November 2015 are recorded.
Back to TopTop