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).

You can use AgNO3 in CH3CN solvent (0.1 M) with a wire of Ag.

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.

Cobaltocen or Cobaltocenium [Cp2Co]+ or decamthylferrocen

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

Can use DMSO, DMF instead of acetonitrile.

@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

Chem Rev 1996, 96, 877 - 910