Controlled Synthesis of Thiazole-Based Polymers and Block Copolymers by RAFT Polymerization of Azolyl S-Vinyl Sulfides and Metal Complexation
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- 作者：Kazuhiro Nakabayashi ; Aiko Matsumura ; Yohei Abiko ; Hideharu Mori
- 刊名：Macromolecules
- 出版年：2016
- 出版时间：March 8, 2016
- 年：2016
- 卷：49
- 期：5
- 页码：1616-1629
- 全文大小：787K
- ISSN：1520-5835
文摘
We studied the RAFT polymerization of five S-vinyl sulfide derivatives containing azole units, including 2-benzothiazolyl vinyl sulfide (BTVS), 2-thiazolyl vinyl sulfide (2-TVS), 1,3,4-thiadiazolyl vinyl sulfide (1,3,4-TVS), 5-methyl-1,3,4-thiadiazolyl vinyl sulfide (M-1,3,4-TVS), and 5-phenyl-1,3,4-oxadiazolyl vinyl sulfide (P-1,3,4-OVS). The polymerization of BTVS using dithiocarbamate-type and trithiocarbonate-type chain transfer agents (CTAs) was controlled, as shown by the relatively low polydispersities of the polymers and the linear increase in molecular weight with increasing conversion. In addition, the molecular weight could be controlled by adjusting the monomer-to-CTA ratio. The thiazole-, thiadiazole-, and oxadiazole-based polymers with relatively narrow molecular weight distributions and predetermined molecular weights were obtained by RAFT polymerization of all monomers using the dithiocarbamate-type CTA. The formation of metal complexes between the azole-containing polymers and various metal species was investigated, concerning their optical and electrochemical behaviors, and the assembled structures of the metal–azole complexes. Among the combinations of the five polymers and three metal species (Cu, Zn, and Ni), the complexation between poly(BTVS) and copper species was the most strongly coordinating, affording a stable metal complex, poly(BTVS)-Cu. The fluorescence behavior of poly(BTVS)-Cu, which is induced by increasing the length of the conjugated structure between the benzothiazole rings and copper species, was controlled by the metal content in poly(BTVS)-Cu. The complexation of benzothiazole-based block copolymers, in which only the BTVS segment interacts with the copper species, whereas another styrene segment showed no specific interactions, exhibits characteristics of assembled structures and fluorescent properties.