Design of Multi-center Multi-step Multi-redox Organic and Metallic Hybrid Molecules

近年来，由于新型π偶联材料的制备及其在材料科学中的应用，含有多个氧化还原中心的分子的研究在材料科学领域引起了极大的研究兴趣。此外，这种具有两个以上氧化还原活性金属中心的分子是研究由这些多金属体系衍生的混合价态进行多电子转移过程的一个有吸引力的目标。另一方面，通过利用包含第16族元素的5π和7π电子骨架来设计新的氧化还原活性有机中心的兴趣，使我们探索合成新的含硫和/或硒原子的5元杂环(S)。因此，我们设计了2，3-二取代苯并[b]噻吩和1，3-二取代苯并[c]硫杂苯作为阴极和阳极多重氧化还原活性的有机-金属杂化分子。2，3-二取代苯并[b]…以苯并[b]噻吩苯或邻苯二甲酰二氯为起始原料，分别系统地、选择性地合成了较多的菲类化合物、1，3-二取代苯并[c]噻吩类化合物和1，3-二取代苯并[c]硒苯类化合物。通过物理和光谱手段以及X射线结晶学分析对分子进行了表征。含有芳基片段的硫基苯衍生物的循环伏安曲线显示，异常稳定的5π硫基阴离子和7π硫基阴离子形成了明确的可逆的阳极和阴极步骤。含二茂铁基片段的新型硫基苯衍生物的循环伏安曲线显示，一个明确的可逆阴极台阶来自异常稳定的7π硫基苯基阴离子，两个明显的可逆阳极台阶来自二茂铁阳离子，它们之间由一个噻吩杂环隔开。用电子自旋共振波谱测定了几种新的7π硫基苯基阴离子的自由基性质。较少

In recent years, the study of molecules comprising multiple reduction-oxidation (redox) centers have attracted considerable research interest in the field of material science due to the preparation of new π-conjugated materials with application in material science. Moreover, this kind of molecule having more than two redox-active metal centers is a fundamentally attractive target for the study of multi-electron transfer processes via the mixed valence state derived from these multi-metallic systems. On the other hand, interest in the design of novel redox-active organic centers by the use of a 5π- and 7π-electron framework containing group 16 elements has led us to explore the synthesis of new 5-membered heterocycles containing sulfur and/or selenium atom(s). Therefore, we have designed 2,3-disubstituted benzo[b]thiophene and 1,3-disubstituted benzo[c]chalcogenophene as both cathodic and anodic multiple-redox active organic-organometallic hybrid molecules. 2,3-Disubstituted benzo[b]thi … More ophenes, 1,3-disubstituted benzo[c]thiophenes, and 1,3-disubstituted benzo[c]selenophene have been systematically and selectively synthesized from benzo[b]thiophene or phthaloyl dichloride as a starting material, respectively. Characterization of the molecules was performed by physical and spectroscopic means and X-ray crystallographic analyses. The cyclic voltammograms of the chalcogenophene derivatives containing aryl fragments showed well-defined reversible both anodic and cathodic steps derived from the unusually stable 5π chalcogenophene radical cations and 7π chalcogenophene radical anions. The cyclic voltammograms of the novel chalcogenophene derivatives containing ferrocenyl fragments showed a well-defined reversible cathodic step derived from the unusually stable 7π chalcogenophene radical anions and two distinct reversible anodic steps derived from ferrocenium cations separated from each other by a thiophene-heterocycle. The radical character of several novel 7π chalcogenophene radical anions was measured by ESR spectroscopy. Less