Electropolymerizable 2,2'-Carboranyldithiophenes. Structure-Property Investigations of the Corresponding Conducting Polymer Films by Electrochemistry, UV-Visible Spectroscopy and Conducting Probe Atomic Force Microscopy
Electropolymerizable 2,2'-Carboranyldithiophenes. Structure-Property Investigations of the Corresponding Conducting Polymer Films by Electrochemistry, UV-Visible Spectroscopy and Conducting Probe Atomic Force Microscopy
复制标题
DOI：
10.1021/ma802369z
复制
发表时间：
2009-04-28
期刊：
影响因子：
5.5
通讯作者：
Vicente, M. Graca H.
中科院分区：
文献类型：
--
作者：
Barriere, Frederic;Fabre, Bruno;Vicente, M. Graca H.
碳硼烷官能化的导电聚合物膜已经在二氯甲烷中由连接到两个2-噻吩基单元的邻-（1）、Meta-（3）和对-碳硼烷（4）异构体的阳极氧化产生。相应的电化学响应的特征在于对应于聚噻吩主链的p-掺杂/去掺杂的宽可逆氧化还原体系，其形式电位从约100 μ mol/L到约100 μ mol/L以poly（1）< poly（3）< poly（4）的顺序增加。0.50至1.15 V vs Ag/Ag+ 10（-2）M。从进一步的UV-可见光谱分析，对于聚（I）、聚（3）和聚（4），光学带隙分别估计为1.8、2.0和2.2eV。聚（1）的更多共轭和双链特征归因于由单体中的分子内β-β '环化反应产生的共轭主链的更多平面构象，从而产生稠合的共轭聚合物。使用DFT方法的分子模拟计算支持这一假设。通过导电探针原子力显微镜评价了电聚合膜的表面形貌和导电域图。这三种聚合物表现出相当相似的形态特征和类似于2 nm的表面粗糙度。导电AFM针尖-碳硼烷聚合物-ITO结的电流-电压（I-V）特性表明，聚（1）具有最高的导电性。
Carborane-functionalized conducting polymer films have been electrogenerated in dichloromethane from the anodic oxidation of ortho- (1), meta- (3) and para-carborane (4) isomers linked to two 2-thienyl units. The corresponding electrochemical response was characterized by a broad reversible redox system corresponding to the p-doping/undoping of the polythiophene backbone, the formal potential of which increased in the order poly(1) < poly(3) < poly(4), from ca. 0.50 to 1.15 V vs Ag/Ag+ 10(-2) M. From further UV-visible spectroscopy analysis, the optical band gap was estimated at 1.8, 2.0 and 2.2 eV for poly(I), poly(3) and poly(4), respectively. The more conjugated and electroconductive character of poly(1) is ascribed to a more planar conformation of the conjugated backbone resulting from an intramolecular beta-beta' cyclization reaction in the monomer, consequently yielding a fused conjugated polymer. Molecular modeling calculations using the DFT method support this hypothesis. The surface topography and maps of the conductive domains of the electropolymerized films were evaluated by conducting probe AFM. The three polymers exhibit fairly similar morphological characteristics and a surface roughness of similar to 2 nm. Current-voltage (I-V) characteristics of conducting AFM tip-carborane polymer-ITO junctions showed that poly(1) had the highest conductivity.