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

Materials

Hiroki Fukumoto¹  Hisashi Nakajima²  Takahiro Kojima³ 

[1] 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; E-Mail:;Institute of Advanced Energy, Kyoto University, Gokasyo, Uji 611-0011, Japan; E-Mail:

关键词: π-conjugated polymer;    indigo;    polycondensation;    H-chromophore;   

DOI  :  10.3390/ma7032030

来源: mdpi

【 摘 要 】

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 (M_w) 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 M_w 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.

【 授权许可】

CC BY   
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