Just looking for another electrochemical system to use as an internal standard for an organic system of mine. Ferrocene oxidation happens to occur exactly at the same potential (well within 0.05V) as my analyte, I am slso thinking my analyte is reacting with either the neutral or oxidised ferrocene; so no background correction.
You can use AgNO3 in CH3CN solvent (0.1 M) with a wire of Ag.
Its been a while, but Ruthenium tris(2,2'-bipyridine) cation will work in organic solvents? Or maybe methyviologen or benzylviologen (maybe with a PF6 counter ion if it isn't soluble enough)?
You could always try versions of ferrocene such acetylferrocene (Eo = 0.75 V), diacetylferrocene (Eo = 1.1 V), decamethylferrocene (Eo = -0.08 V). This will provide you with a 1.2 V window. You could always try colbaltacenium (PF6 salt) if you need something in the reduction window.
I looked at my thesis. I have methyl viologen (PF6 salt) in acetonitrile with Bu4N[PF6] electrolyte at about -0.45 V vs SCE (aqueous SCE stuck in solution, not corrected for junction potentials between the aqueous and organic compartments).
Ag/AgCl can be used in MeOH and Water with the Temp > 0C
Ag/AgNO3 can be used in MeCN with the Temp > -40C
Yes Cobaltocene is more appropriete reference in ionic liquids for exemple see publication in JACS for Angel Toriero
Ag/AgCl can be used with 0.5 HCOOH + 0.5 H2SO4 at room temperature. This is what I using for my Thesis current.
Bis(biphenyl)chromium/bis(biphenyl)chromium is also recommended by IUPAC besides ferrocene as a reference redox systems for non-aqueous solvents. Worked fine in some ionic liquids/deep eutectic solvents.
You can use tetrabutylammonium perchlorate (TBAP) redox system as supporting electrolyte or internal standard for your organic system.
I would also try with the Ag+/Ag couple in any of its variants. Probably the best, in order to avoid interferences or reactions with the solvent or the analyte, would be to fabricate a deposit of silver chloride on a silver wire (you just have to polarize your silver wire positive enough in a chloride containing solution) and to immerse the silver chloride-covered wire in a saturated solution of NaCl or KCl in your organic solvent, and use this whole thing as a reference electrode.
Thank you all for your answers, all a real help. Had to go with cobalt/acetyl ferrocene/ chromium standards, I'll check which one I can get my hand on soonest . Don't have the luxury of working in acetonitrile.
Fe(C5H5)2+ + e- ⇌ Fe(C5H5)2 E = 0 (by definition)
Fe(C5Me5)2+ + e- ⇌ Fe(C5Me5)2 E = −0.59V
Co(C5H5)2+ + e- ⇌ Co(C5H5)2 E = −1.33
Co(C5Me5)2+ e- ⇌ Co(C5Me5)2 E = −1.94
@David Summers:
Ru-tris(bipy) perchlorate salt is soluble in polar organic solvents. It can be made from the di-chloride by simple recrystallization in excess.
See here:
N. E. Tokel-Takvoryan, R. E. Hemingway and A. J. Bard, "Electrogenerated Chemiluminescence. XIII. Electrochemical and ECL Studies of Ruthenium Chelates," J. Am. Chem. Soc., 95, 6582 (1973).
I had this exact same problem and used Decamethylferrocene. Others in my lab used cobaltocene when ferrocene wouldn't work (but cobaltocene is more sensitive than decamethylferrocene).
See: http://pubs.acs.org/doi/abs/10.1021/jp991381+ for the decamethylferrocene redox potentials in various solvents.
Cheers,
Kyle
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