Short communication, Note

https://doi.org/10.5562/cca3553

Electrofugality of Some Ferrocenylphenylmethyl Cations

Sandra Jurić ; University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, HR-10000 Zagreb, Croatia
Marijan Marijan ; University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, HR-10000 Zagreb, Croatia
Olga Kronja ; University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, HR-10000 Zagreb, Croatia

Abstract

The electrofugality scale has been extended with new substituted ferrocenylphenylmethyl cations 1-4. Ef values were determined by applying the linear free energy relationship (LFER): log k = sf (Ef + Nf). Due to ability of the ferrocene moiety to efficiently stabilize the positive charge, ferrocenylphenylmethyl cations constitute a group of very powerful electrofuges (Ef > 1). Impact of the phenyl group in ferrocenylphenylmethyl derivatives on stabilization of the positive charge is considerably leveled by the ferrocenyl group, so the rate effect of the alkyl substituents (methyl, ethyl and tert-butyl) on the phenyl ring is suppressed, causing narrow range of Ef parameters. Lack of breakdown of Hammett-Brown plot if the rates for the complete set of substrates 1–5 have been correlated, indicates that the ferrocenyl group in α-position diminishes the stabilizing effects of electron-donating substituents as well.

This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords

electrofugality; nucleofugalty; ferrocenylphenylmethyl cation; solvolysis; substituent effect

Hrčak ID:

225522

URI

https://hrcak.srce.hr/225522

Publication date:

29.7.2019.

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