Trifluoromethanesulfonate anion

Earle et al reported the first proof of the paradigm that the outcome of a chemical reaction can be radically altered by the choice of the ionic liquid as the solvent for the catalyst. The reactants were toluene and nitric acid in HCl for the following three ILs (1) [bmim][OTf, (2) [bmim][X], and (3) [bmim][OMs] where OTf is the trifluoromethanesulfonate anion, X = halide, and OMs = methanesulfonate salt. The reactions observed are described in Scheme 1. 

The values of heat capacities of 24 ILs, pyridinium-based, imidazolium, and ammonium ILs were presented by the same laboratory a year later [195]. The high value (766 J mol K at 298 K) was observed for l-hexyl-2-propyl-3,5-diethylpyridinium salt, [lCg-2C3-3,5C2py][Tf2N]. It was found that heat capacity increases linearly with increasing molar mass for these compounds that are comprised of a limited number of different atoms. A series of pyri-dinium and imidazolium-based ILs mainly with trifluoromethanesulfonate anion, [TfO], have been measured by Diedrichs and Gmehling [124]. The values between 300 and 800 J mol K were observed for different ILs. 

The presence of two signals in the 19F NMR spectra in a 1 7 integral ratio indicates encapsulation of one of the eight trifluoromethanesulfonate counterions inside the cage. An X-ray crystal structure of 9d (Figure 7.3) confirms the inclusion of a single, desolvated trifluoromethanesulfonate anion inside the cavity [23],... 

Explain why the trifluoromethanesulfonate anion is a better leaving group than the mesylate anion. 

The trifluoromethanesulfonate anion can be exchanged for iodide by treating the 1,3-benzotellurazolium salts with sodium iodide in acetone . ... 

Very low basicity and nucleophilicity made the trifluoromethanesulfonate anion (TfO ) the counterion of choice for labile cationic species as in dication salts 53 and 54, which were characterized by FD, FAB and 252Cf-Plasma Desorption mass spectrometry40. In the FD mass spectrum of 53, the noteworthy presence of the dication itself ([D]2 + ) was found, giving the base peak, accompanied by a cation triflate cluster [D OTf]+ and fragment ions, involving cleavage at the ether bond. 

Complexes of trifluoromethanesulfonate anion with cobalt(III) are labile oward substitution under mild conditions, and they have proved to be useful synthetic precursors to a variety of aminecobalt(III) complexes. The pentaammine-(trifluoromethanesulfonato-O)rhodium(III) ion, which is readily prepared from [Rh(NH3)5Cl]Cl2 in hot CF3SO3H, is also versatile as a synthetic precursor. " Its synthesis and solvolysis to give essentially quantitative yields of the penta-ammineaqua- and hexaamminerhodium(III) ions are described below. The aqua complex has previously been prepared by the base hydrolysis or Ag -induced aquation of [Rh(NH3)5Cl]Cl2 in water, but the present method presents a cleaner and more rapid alternative. The methods for preparation of the [RhCNHj) ] ion have evolved from the procedure of J0rgensen. They involve prolonged reaction of [Rh(NH3)5Cl]Cl2 with ammonia in a pressure vessel at elevated temperature. The solvolysis of [Rh(NH3)5(0S02CF3)](CF3S0j)2 in liquid ammonia is a simple, high-yield, and rapid alternative. 

Fig. 7. Less known data on weak anions adsorption on platinum obtained by the conductivity technique. Curves 2 are given for comparison, measured in 2.5 mM H2SO4 by the same technique at the same electrodes. (a) Trifluoromethanesulfonic anion adsorption from 5 mM CF3SO3H solution (curve 1), compared also with the data for 5 mM CF3COOH (curve 3). (b) Fluoroborate adsorption from 6 mM HBF4 solution (curve 1) compared with the available earlier data of isoelectric potential shifts for Fh+ in 10 mM HBF4 solution (points). To compare roughly with fluoride adsorption,curve 3 for 0.14 M HF is presented (the activity of hydronium ion in this solution is the same as in 10 mM H2SO4). Reprinted from Refs. 59 (a) and 157 (b). Copyright (1981) and (1977), respectively, with permission from Nauka Publ.

HOMOLEPTIC TRANSITION METAL ACETONITRILE CATIONS WITH TETRAFLUOROBORATE OR TRIFLUOROMETHANESULFONATE ANIONS... 

The poly(sulfonium cation) with trifluoromethanesulfonate anion is a new type polyelectrolyte which has alternative structure of positively charged phenylsulfonium and phenylsulfide. The solution viscosity and solubility of a polyelectrolyte are influenced by a co-existence of supporting electrolyte and solvent species. The poly( sulfonium cation) is insoluble in aqueous solution but soluble in polar organic solvents, e,g. acetone, acetonitrile and dimethyl sulfoxide (DMSO). In particular, the polycation is very soluble in acetonitrile and formic acid (solubility more than 100 mg mL-i)-... 

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