I have Bu4NBF4, Bu4NPF6, Bu4NClO4. Please tell me which electrolyte should I take for reduction in DMF to about -3V (vs. Fc)?
Sometimes, the behavior of an analyte in cyclic voltametry can be strongly influenced by the nature of the cation or the anion of the supporting electrolyte. Thus, according to me, the best way is to record cyclic voltamograms of the analyte in the presence of each electrolyte in the same conditions (concentrations of the analyte and the supporting electrolyte, scan rate, parameters of the potentiostat) and compare the signals obtained.
Nguelo Bruno Please tell me what are the wide range of potentials in DMF? (in your experience)
Dear Natalia V. Zolotareva ,
redox chemistry (relative to bulk solution) only[1] occurs inside[1,2] the electrical double layer at your WE (Working electrode).
So, what is your WE[3] ?
1. Fundamental inorganic electrochemistry - potential sweep voltammetry http://alpha.chem.umb.edu/chemistry/ch371/documents/Echem.pdf
2. Role of Electrostatics in Influencing the Pathway by which the Excited State https://pubs.acs.org/doi/suppl/10.1021/acs.jpca.9b04427/suppl_file/jp9b04427_si_001.pdf
3. Quot. from your Question: ... I have Bu4NBF4, Bu4NPF6, Bu4NClO4. Please tell me which electrolyte should I take for reduction in DMF to about -3V (vs. Fc)?
I usually work in aqueous solutions, but here is a paper in which you can find the potential window of DMF.
Vadim S. Gorshkov
I agree))) I am a beginner electrochemists. I want to speak to colleguages...
Dear Natalia V. Zolotareva ,
try to follow Vadim S. Gorshkov
's advice.If not, then send (a link for) the specs of "GC" (your WE)[1].
1. My WE is GC (in ElectraSyn 2.0).
Ioannis Samaras This is my WE https://www.ika.com/en/Products-Lab-Eq/Electrochemistry-Kit-csp-516/CV-Glassy-carbon-cpdt-40002863/
Dear Natalia V. Zolotareva ,
try to follow Vadim S. Gorshkov
's advice.I am afraid, that the surface of your GC (Glassy Carbon, as WE) will be modified at such high values of the potential range (in DMF, CV to about -3V vs. Fc).
Do you have a spare Pt-electrode, that you could use as an alternative WE, for this study ?
Since you have a 2nd Pt electrode (as a WE), then start some new CV-tests and compare these CVs with your older (Glassy Carbon, as a WE) CVs.
Ioannis Samaras Ok. In my case, the DMF has impurities and I cannot reach the indicated values.
Dear Natalia V. Zolotareva ,
you must have (buy or even borrow by following Vadim S. Gorshkov
's advice) a kind of a minimum impurities solute. You need, at least an anhydrous-DMF[1,2], for your reference[3] solute or solution; it will help to find out[4]: how you could manage/control[5] some of the (solute's) specific[4] impurities, in your case study.1. N,N-Dimethylformamide, anhydrous ≥99.9% amine-free https://us.vwr.com/store/product/7985131/n-n-dimethylformamide-anhydrous-99-9-amine-free
2. N,N-Dimethylformamide anhydrous, [ZerO2®, 99.8%] https://www.sigmaaldrich.com/catalog/product/sial/900638?lang=en®ion=GR&cm_sp=Insite-_-prodRecCold_xviews-_-prodRecCold10-3
3. N,N-Dimethylformamide [analytical standard] https://www.sigmaaldrich.com/catalog/product/sial/72438?lang=en®ion=GR&cm_sp=Insite-_-prodRecCold_xviews-_-prodRecCold10-5
4. NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist http://ccc.chem.pitt.edu/wipf/Web/NMR_Impurities.pdf
5. Impurity Case Studies: Control of Potential Genotoxic Impurities in DMF http://pharmacentral.in/wp-content/uploads/2019/04/D2S07-Liao-Keck.pdf
@ Ioannis Samaras Thank you so much! I did an NMR spectrum of my DMF. We already ordered anhydrous DMF earlier, but so far there have been no deliveries.
In order to choose an electrolyte you need to decide on the working window. For example, for the anode region the best option is PF6-; for the cathode region is Et4N+.
See Kosuke Izutsu Electrochemistry in Nonaqueous
Solutions, ISBN: 978-3-527-32390-6
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