Anodic oxidation of organometallic sandwich complexes using [Al(OC(CF3)3)4]− or [AsF6]− as the supporting electrolyte anion

Taming the Cationic Beast: Novel Developments in the Synthesis and Application of Weakly Coordinating Anions

“…[437] Them ore bespoke [B(Ar Rf ) 4 ] À ion (where Rf = (CF 2 ) 5 CF 3 )h as been shown to permit the use of perfluorinated solvents of very low polarity. [441,442] Electrolytes containing WCAsc an also be applied to study the electrochemistry of multiply charged complexes,as the species formed retain their solubility and show areduced tendency to be deposited on the electrode.M oreover,t he reduced levels of ion pairing from WCAsallow the separation of oxidation events.T his is readily demonstrated by the separation of the two sequential one-electron oxidations of bis(fulvalene)dinickel, where the spread of E 1/2 potentials observed using differing [NBu 4 ] + -based electrolytes in dichloromethane shows significant anion dependence.A s the anion becomes more weakly coordinating,t he spread of E 1/2 potentials increases,w ith chloride,[ PF 6 ] À ,a nd [B-(C 6 F 5 ) 4 ] À having DE 1/2 values of 270 mV,4 40 mV,a nd 750 mV,r espectively. [ B(Ar CF3 ) 4 ] À ,[ B(C 6 F 5 ) 4 ] À ,o r[ Al-(OR F ) 4 ] À )c ontaining electrolyte has been shown to permit the reversible one-electron oxidation of Cp 2 Ru, rather than the single irreversible two-electron process reported for traditional anions.…”

“…[ B(Ar CF3 ) 4 ] À ,[ B(C 6 F 5 ) 4 ] À ,o r[ Al-(OR F ) 4 ] À )c ontaining electrolyte has been shown to permit the reversible one-electron oxidation of Cp 2 Ru, rather than the single irreversible two-electron process reported for traditional anions. [442] [435,443] This separation is increased even further by the use of the very weakly coordinating [Al-(OR F ) 4 ] À anion, where DE 1/2 = 769 mV.…”

Reversible σ‐Dimerizations of Persistent Organic Radical Cations

“…[13] Cyclic voltammetry of them in CH 2 Cl 2 at room temperature with nBu 4 N[Al(OR F ) 4 ] [14] as a supporting electrolyte showed well-defined reversible oxidation waves at different scans ( Figure 1; Supporting Information, Figure S1), indicating radical cations 1C + , 2C + , and 3C + are stable under these conditions. [13] Cyclic voltammetry of them in CH 2 Cl 2 at room temperature with nBu 4 N[Al(OR F ) 4 ] [14] as a supporting electrolyte showed well-defined reversible oxidation waves at different scans ( Figure 1; Supporting Information, Figure S1), indicating radical cations 1C + , 2C + , and 3C + are stable under these conditions.…”

The electrochemical oxidation of ruthenocene in various room temperature ionic liquids

“…The fit between experimental and theoretical data was optimized by inputting a value for r d (calibrated previously) and instructing the software to iterate through various D and nc values (where n is the number of electrons). An average D value of 2.20 Â 10 À11 m 2 /s was determined, which is approximately two orders of magnitude smaller than values reported in conventional solvents (2.50 Â 10 À9 m 2 /s in acetonitrile [12] and 2.10 Â 10 À9 m 2 /s in dichloromethane [25]); this result is due to the increased viscosity of the ionic liquid (52 cP compared to 0.34 cP for MeCN and 0.44 cP for DCM), and comparable with that achieved for ferrocene in the same IL (3.77 Â 10 À11 m 2 /s [11]) with the slightly slower diffusion of RuCp 2 reflecting the larger size compared to FeCp 2 . An nc value of approximately 19 mM was obtained.…”

“…This dicationic dimer has been isolated previously [15,16,25] and has been shown to be favoured over the monocationic dimer, [Cp 2 Ru-RuCp 2 ] + . Ionic liquids have the ability to stabilize the highly charged dimer, and the species becomes reduced at lower potentials, directly back to neutral ruthenocene, which possibly suggests that this process, shown in Eq.…”