Tetrathia[7]helicene-Based Complexes of Ferrocene and (畏5-Cyclohexadienyl)tricarbonylmanganese: Synthesis and Electrochemical Studies

详细信息    查看全文

• 作者：Fran莽oise Rose-Munch ; Ming Li ; Eric Rose ; Jean Claude Daran ; Alberto Bossi ; Emanuela Licandro ; Patrizia Romana Mussini
• 刊名：Organometallics
• 出版年：2012
• 出版时间：January 9, 2012
• 年：2012
• 卷：31
• 期：1
• 页码：92-104
• 全文大小：593K
• 年卷期：v.31,no.1(January 9, 2012)
• ISSN：1520-6041

文摘

Tetrathia[7]helicene ([7]TH)-based complexes substituted at the thienyl ring ends by a ferrocenyl group (Fc) or by a (畏⁵-cyclohexadienyl)Mn(CO)₃ derivative have been prepared by Sonogashira coupling reactions starting from the mono- or diiodo [7]TH compounds. The molecular structure of one of the diferrocenyl [7]TH complexes was established by X-ray analysis. Electrochemical investigation on the Fc-[7]TH systems show that the Fc groups are significantly electron poorer with respect to Fc (螖E掳 鈮?0.15 V), due to the effective conjugation of the Fc redox moiety with the triple bond + helicene system, as also confirmed by spectroscopic data. Potential cycling around the second oxidation peak, assigned to the thiahelicene moiety, affords fast, regular growth of electrodeposited conducting films, provided that one terminal 伪-thiophene position be available for coupling; on the other hand, long alkyl chains hamper film formation. The conducting films feature a broad oxidation wave resulting from the merging of several redox peaks, having its onset at the Fc oxidation. Since conducting films obtained by electrooligomerization of parent tetrathiahelicene have their onset potentials 0.45 V more positive than the Fc redox sites in this studied Fc-[7]TH conjugates, the above continuity could point to some coupling between Fc redox centers and conjugated 蟺 systems, favored by solid-state stacking.