Prasad, N., Main, L., Nicholson, B.K. & McAdam, C.J. (2010). 2-Ferrocenyl-substituted pyrylium ions from coupling of ethynylferrocene with cyclomanganated chalcones. Journal of Organometallic Chemistry, 695(17), 1961-1965.
Permanent Research Commons link: http://hdl.handle.net/10289/4086
2-Ferrocenyl-substituted pyrylium salts are produced when orthomanganated chalcones are reacted with ethynylferrocene in CCl4. When the reaction is carried out in benzene, intermediate ferrocenyl-substituted (η5-pyranyl)Mn(CO)3 species can be isolated which give the pyrylium cations on oxidation. The electrochemistry of the 2-ferrocenyl-pyrylium cations shows both oxidation (of the ferrocenyl) and reduction (of the pyrylium) processes, and the UV–visible spectra show a broad band at ca 680 nm which can be assigned to an intramolecular charge transfer transition.