Syntheses, Spectroelectrochemical Studies, and Molecular and Electronic Structures of Ferrocenyl Ene-diynes
| Autor: | Kevin B. Vincent, Matthias Parthey, Judith A. K. Howard, Martin Kaupp, Paul J. Low, Qiang Zeng, Dmitry S. Yufit, František Hartl |
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| Rok vydání: | 2013 |
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| Zdroj: | Organometallics. 32:6022-6032 |
| ISSN: | 1520-6041 0276-7333 |
| Popis: | The readily available complex 1,1-dibromo-2-ferrocenylethylene provides a convenient entry point for the preparation of a wide range of cross-conjugated 1,1-bis(alkynyl)-2-ferrocenylethenes through simple Pd(0)/Cu(I)-mediated cross-coupling reactions with 1-alkynes. The ferrocene moiety in compounds of the general form FcCH═C(C≡CR)2 is essentially electronically isolated from the cross-conjugated π system, as evidenced by IR and UV–vis spectroelectrochemical experiments and quantum chemical calculations. In contrast to the other examples which give stable ferrocenium derivatives upon electrochemical oxidation, the aniline derivatives [FcCH═C(C≡CC6H4NH2-4)2]+ and [FcCH═C(C≡CC6H4NMe2-4)2]+ proved to be unstable on the time scale of the spectroelectrochemical experiments, leading to passivation of the electrode surface over time. There is no significant thermodynamic stabilization of the radical anion [FcCH═C(C≡CC6H4NO2-4)2]− relative to the neutral and dianionic analogues, although the dianion [FcCH═C(C≡CC6... |
| Databáze: | OpenAIRE |
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