Synthesis and electrical conductivity of perchlorate-doped TTF–diamide nanofibers with double and triple helix structures
作者:Sejung Ahn、Yukyung Kim、Seungjae Beak、Shohei Ishimoto、Hideo Enozawa、Eigo Isomura、Masashi Hasegawa、Masahiko Iyoda、Yungwoo Park
DOI:10.1039/c0jm02628j
日期:——
We synthesized 4,5-bis(octadecylthio)-4â²,5â²-bis(ethylcarbamoyl)tetrathiafulvalene and measured the electrical conductivity of its perchlorate (ClO4â)-doped nanofibers, which have double and triple helix structures. The nanostructure of the bis(octadecylthio)-TTFâdiamide and its ClO4â-doped fibers in a 3â:â1 ratio was deduced in relation to the X-ray crystal structure of bis(methylthio)-TTFâdiamide. The doubly coiled nanofibers form when initially formed spiral ribbons of lamellarly arranged TTFâdiamide perchlorate split in the middle, and a further split of the double helix produces the triplex structure. Temperature-dependent conductance and currentâvoltage (IâV) characteristics of the coiled fibers were measured in the temperature (T) range of 70â300 K. The conductance decreased with a decrease in T, and the IâV characteristics were nonlinear over the entire T range. The results were analyzed by using a modified fluctuation-induced tunneling conduction model, where the barrier height and width were linearly dependent on the electric field.
我们合成了4,5-双(十八烷硫基)-4â²,5â²-双(乙基氨基甲酰基)四硫代富勒烯,并测量了其高氯酸盐(ClO4â)掺杂纳米纤维的导电性,这些纤维具有双螺旋和三螺旋结构。根据双(甲硫基)-TTFâdiamide 的 X 射线晶体结构,推断出双(十八烷基硫基)-TTFâdiamide 及其 ClO4â 掺杂纤维的纳米结构比例为 3â:â1。双线圈纳米纤维是由最初形成的层状排列的高氯酸TTFâdiamide螺旋带从中间分裂开来形成的,双螺旋的进一步分裂产生了三重结构。在 70-3000 K 的温度(T)范围内,测量了盘绕纤维随温度变化的电导率和电流电压(IV)特性。我们使用改进的波动诱导隧道传导模型对结果进行了分析,在该模型中,势垒高度和宽度与电场呈线性关系。