作者:Barbara Tsuie、Jerry L. Reddinger、Gregory A. Sotzing、Jadwiga Soloducho、Alan R. Katritzky、John R. Reynolds
DOI:10.1039/a903374b
日期:——
The synthesis, characterization, and electrochromic properties of copolymers derived from 9,9-dialkyl-2,7-dibromofluorene (18a, alkyl=C
10
H
21
; 24, alkyl=Et) and pyrrole, thiophene, 3,4-ethylenedioxythiophene, and furan are described. Two synthetic routes to 9,9-diethyl-2,7-bis(pyrrol-2-yl)fluorene (30) afford product in 30% and 20% yields, respectively. Monomer 30 undergoes electropolymerizationto yield electroactive polymer films. The lowest monomer oxidation potential (E
p,m
=0.4 V vs. Ag/Ag
+
) is found in tetraethylammonium tosylate (TEATOS)-CH
3
CN, but film formation is slow. Spectroelectrochemical analysis of poly(30) reveals a band gap at 2.4 eV and upon polymer oxidation, two low energy absorptions peaking at 1.2 and 2.2 eV appear. This phenomenon is attributed to formation of bipolaron bands between the valence and conduction bands. Soluble fluorene-heterocycle polymers 34a-d have been synthesized by the Stille coupling reaction of 18a and 2,5-bis(trimethylstannyl)thiophene (21a), 5,5′-bis(trimethylstannyl)-2,2′-bithiophene (21b), 2,5-bis(trimethylstannyl)-3,4-ethylenedioxythiophene (21c), and 2,5-bis(trimethylstannyl)furan (22), respectively, in high yields. The NMR spectra are consistent with the proposed structures of the polymers 34a-d, and no evidence of ring opening of the furyl unit in 34d is seen in the NMR and IR spectra. The molecular weights of 34a-d are in the range of 8000 g mol
–1
with polydispersity indices (PDI) of 2. Polymers 34a-c have band gaps measured at 2.4 eV, while polymer 34d has its gap at 2.6 eV. Polymers 34a-c undergo solution doping with SbCl
5
to form new low energy bipolaron bands at the expense of the absorption in the UV-VIS. However, polymer 34d does not oxidatively dope with SbCl
5
.
描述了从9,9-二烷基-2,7-二溴芴(18a,烷基=C10H21;24,烷基=Et)和吡咯、噻吩、3,4-亚乙基二氧噻吩以及呋喃衍生的共聚物的合成、表征和电致变色性质。两条合成9,9-二乙基-2,7-双(吡咯-2-基)芴(30)的路线分别获得了30%和20%的产率。单体30经电化学聚合生成电活性聚合物薄膜。最低单体氧化电位(Ep,m=0.4 V vs. Ag/Ag+)在四乙基铵对甲苯磺酸盐(TEATOS)-CH3CN中观察到,但薄膜形成缓慢。光谱电化学分析发现聚30的带隙为2.4 eV,聚合物氧化后出现两个低能量吸收峰,峰值为1.2 eV和2.2 eV,这一现象归因于价带和导带之间双极化子带的形成。通过Stille偶联反应,18a分别与2,5-双(三甲基锡基)噻吩(21a)、5,5′-双(三甲基锡基)-2,2′-双噻吩(21b)、2,5-双(三甲基锡基)-3,4-亚乙基二氧噻吩(21c)和2,5-双(三甲基锡基)呋喃(22)反应,合成了可溶性芴-杂环聚合物34a-d,产率较高。NMR光谱与所提出的聚合物34a-d的结构一致,NMR和IR光谱中未观察到34d中呋喃单元的开环证据。34a-d的分子量在8000 g mol–1范围内,多分散性指数(PDI)为2。聚合物34a-c的带隙测得为2.4 eV,而聚合物34d的带隙为2.6 eV。聚合物34a-c通过溶液掺杂SbCl5形成新的低能量双极化子带,以牺牲紫外-可见光吸收为代价。然而,聚合物34d不能通过SbCl5进行氧化掺杂。