Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada.
J Org Chem. 2011 Apr 15;76(8):2701-15. doi: 10.1021/jo2000447. Epub 2011 Mar 21.
Alkynyl-substituted phenyldithiafulvenes have been found to act as versatile building blocks for the construction of π-conjugated molecular rods, shape-persistent macrocycles (SPMs), and conducting polymers. Through Cu(I)-catalyzed alkynyl homocoupling, a series of linear-shaped π-extended tetrathiafulvalene analogues (exTTFs) carrying conjugated oligoynes (ranging from diyne to hexayne) as the central π-bridge were readily prepared. The solid-state properties and reactivities of diyne- and tetrayne-centered exTTFs were characterized by X-ray crystallography and differential scanning calorimetry (DSC), while the electronic properties of the oligoyne-exTTFs were elucidated by UV-vis absorption spectroscopy and density functional theory (DFT) calculations. Cyclic voltammetric analysis showed that the terminal phenyldithiafulvene groups of the oligyne-exTTFs could undergo oxidative coupling to form tetrathiafulvalene vinylogue (TTFV)-linked polymer wires. Through a different synthetic route involving oxidative dimerization and Pd/Cu-catalyzed alkynyl homocoupling, the acetylenic phenyldithiafulvene precursors led to shape-persistent macrocycles where the formation of trimeric macrocycles was particularly favored due to the small ring strain incurred. Finally, spectroelectrochemical studies on these oligoyne and TTF hybrid materials disclosed electrochromic and molecular redox-controlled switching properties applicable to molecular electronic and optoelectronic devices.
炔基取代的苯并二硫杂富烯已被发现是构建π共轭分子棒、形状保持大环（SPM）和导电聚合物的多功能构建块。通过 Cu(I) 催化的炔基同偶联反应，很容易制备了一系列带有共轭寡炔（从二炔到六炔）作为中心π桥的线性扩展四硫富瓦烯类似物（exTTFs）。通过 X 射线晶体学和差示扫描量热法（DSC）对二炔和四炔中心 exTTFs 的固态性质和反应性进行了表征，而通过紫外可见吸收光谱和密度泛函理论（DFT）计算阐明了寡炔-exTTFs 的电子性质。循环伏安分析表明，寡炔-exTTFs 的末端苯并二硫杂富烯基团可以经历氧化偶联形成四硫富瓦烯乙烯基类似物（TTFV）连接的聚合物线。通过涉及氧化二聚和 Pd/Cu 催化的炔基同偶联的不同合成途径，乙炔基苯并二硫杂富烯前体导致形状保持大环的形成，由于发生的小环应变，三聚体大环的形成特别有利。最后，对这些寡炔和 TTF 杂化材料进行了光谱电化学研究，揭示了适用于分子电子和光电设备的电致变色和分子氧化还原控制开关特性。
