Synthesis, Structure, and Redox Chemistry of Ethenyl and Ethynyl Ferrocene Polyaromatic Dyads

详细信息    查看全文

• 作者：Laurence Cuffe ; Richard D. A. Hudson ; John F. Gallagher ; Sarah Jennings ; C. John McAdam ; Rosamond B. T. Connelly ; Anthony R. Manning ; Brian. H. Robinson ; and Jim Simpson
• 刊名：Organometallics
• 出版年：2005
• 出版时间：April 25, 2005
• 年：2005
• 卷：24
• 期：9
• 页码：2051 - 2060
• 全文大小：219K
• 年卷期：v.24,no.9(April 25, 2005)
• ISSN：1520-6041

文摘

A series of ferrocenyl-arene dyads, Fc-CC-Ar, trans-Fc-CH=CH-Ar, and Fc-CH=CH-CH=CH-Ar (Ar = phenyl, 1-naphthyl, 2-naphthyl, 9-phenanthryl, 9-anthryl, 1-pyrenyl,3-perylenyl) have been synthesized. Their structures and spectroelectrochemical propertiesare discussed. The molecular structures of several have been determined by X-ray diffractionand the observed structures compared with global free-energy minimized calculatedstructures. In the solid state all ethynyl dyads have the aromatic ring orthogonal to theferrocenyl cyclopentadienyl rings, whereas calculations predict a coplanar orientation.Calculated and observed structures agree for the ethenyl dyads with the rings orthogonaland coplanar for the anthryl and pyrenyl dyads, respectively. In most cases the solid-statestructures are stabilized by offset -stacking interactions between the polycyclic hydrocarbonrings. The two bands in the electronic spectra of the neutral dyads are due to the individualaryl and ferrocenyl end-groups. Upon oxidation at the [Fc]^+/0 couple, the ferrocenyl transitionis replaced by LMCT bands at lower energy and a new weak band in the NIR assigned to aFc⁺ aryl transition; these assignments are supported by resonance Raman spectra, andthe energy of the Fc⁺ aryl transition correlates with the ionization energy of the arylgroup. These are therefore electrochromic dyads.