Trifluoromethylation of C₆₀and C₇₀with Mercury(II) Trifluoroacetate

Abstract

Fullerenes C 60 and C 70 are shown to react with Hg(CF 3 COO) 2 in the ionization chamber of the electron impact source of a mass spectrometer at 300 and 310uC, yielding trifluoromethylated derivatives of the fullerenes with up to six and two CF 3 addends, respectively. For some of the products the reactions are accompanied by hydrogen addition. Based on previous mechanistic studies of the analogous reactions of C 60 with the Scherer radical (C 9 F 19 N), a mixture of perfluoronones (C 9 F 18 ), and acetone, a plausible scheme is proposed for the processes. It involves formation of the intermediate CF 3 radicals owing to electron impact or thermally initiated homolytic dissociation of the mercury(II) salt, and their further reaction with the fullerenes at the surface of the ionization chamber. Heating mixtures of the reagents under argon at 300-310uC also yields trifluoromethylated fullerenes, in agreement with the results obtained with the ionization chamber.

Homolytic Reactive Mass Spectrometry of Fullerenes: Interaction of C60 and C70 with Ketones in the Electron Impact Ion Source of a Mass Spectrometer and the Comparison of Results with Those of Photochemical Reactions of C60 with Several Ketones in Solution

“…The above mass spectral studies have been undertaken by us not only as ends in themselves, but one of the major tasks of the present work has been to show that analogous reactions between fullerenes and ketones can proceed in solution, and they do react. Under quartz region UV irradiation as the simplest substitute of the irradiation by electrons, C 60 interacts with such ketones as acetone (1), acetophenone (2), phenyl trifluoromethyl ketone (7), and diethyl ketone (11) with the transfer of the corresponding radicals R…”

“…In 2009, we published two papers evidencing that the radical trifluoromethylation, phenylation, and carboranylation of C 60 and C 70 proceeded in the IC when the fullerenes interacted with the corresponding organo-and organoelement mercurials [11,12]. It is worth noting here that in spite of all difference in conditions (high energetic influence over the reactants, the absence of solvent, and so forth), given the evidence that a certain radical reaction proceeds in an IC, one can think about implementing the analogous reaction in solution.…”

“…The choice of ketones as reactants was favored by the fact that their molecular ions dissociate eliminating the corresponding organic radicals, thus providing the possibility for radical functionalization of fullerenes to occur by analogy with trifluoromethylation and so forth reported in references [10][11][12].…”

Interaction of Fullerenes with Organosilanes in the Ionization Chamber of a Mass Spectrometer under Electron Impact and the Reaction of C60with Tetraphenylsilane in Solution under UV Irradiation

“…With that, our purpose was not to investigate these reactions in the IC as the end in themselves but to demonstrate that they can predict the reactivity of the fullerenes toward these reagents in solution or the solid phase/state. Actually, it was done by implementing the reactions of C 60 with compounds of each abovementioned class under UV irradiation or thermally [19][20][21][22][23][24][25][26]. The present study continues investigations in this field.…”

A Comparative Study of Homolytic Reactions of Fullerenes with Aldehydes in a Mass Spectrometer under Electron Impact and in Solution under UV Irradiation

“…Some of these reactions with C 60 have been implemented in solution or solid state, thermally or under ultraviolet (UV) irradiation. [36][37][38][39][40] These studies count in favor of the hypothesis that the homolytic reactive mass spectrometry of fullerenes, i.e. the homolytic reactions of fullerenes with other compounds occurring in the ionization chamber of a mass spectrometer, can serve as a quick tool for elucidating the reactivity of fullerenes in homolytic reactions in solution or in the solid phase/state.…”