Design of Organic-Oraganometallic Hybrid Molecules with Mixed-valence Redox Activity

近年来，由于制备新的π共轭材料并在材料科学中应用，对包含多个氧化还原中心的分子的研究在材料科学领域引起了相当大的研究兴趣。此外，这种分子具有两个以上的氧化还原活性金属中心是一个从根本上有吸引力的目标，通过混合价态来自这些多金属系统的多电子转移过程的研究。另一方面，通过使用含有16族元素的5π-和7π-电子骨架设计新颖的氧化还原活性有机中心的兴趣引导我们探索新的含硫原子的5元杂环的合成。因此，我们设计了由噻吩、二噻吩和三噻吩桥连的低聚二茂铁衍生物作为阴极和阳极多重氧化还原活性的有机-金属有机杂化分子。每一个分子已经系统地和选择性地合成从helofercene或二茂铁基氯化锌通过交叉偶联反应与噻吩或低聚噻吩衍生物。通过物理和光谱手段进行分子的表征。同时含有噻吩和二茂铁片段的新型有机-金属有机杂化分子的循环伏安图显示了由异常稳定的5π噻吩自由基阳离子和7π噻吩自由基阴离子产生的明确的可逆阳极和阴极步骤。此外，分子显示出多个不同的可逆阳极步骤，来自二茂铁阳离子彼此分开的噻吩或低聚噻吩。

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 atom (s). Therefore, we have designed oligo-ferrocene derivatives bridged by thiophene, bithiopehene, and terthiophene as both cathodic and anodic multiple-redox active organic-organometallic hybrid molecules. Each molecule has been systematically and selectively synthesized from heloferrocene or ferrocenylzinc chloride by cross-coupling reactions with thiophene or oligothiophene derivatives. Characterization of the molecules was performed by physical and spectroscopic means. The cyclic voltammograms of the novel organic-organometallic hybrid molecules containing both thiophene and ferrcene fragments showed well-defined reversible both anodic and cathodic steps derived from the unusually stable 5π thiophene radical cations, 7π thiophene radical anions. In addition, the molecules showed multiple distinct reversible anodic steps derived from ferrocenium cations separated from each other by a thiophene or an oligothiophene.