Kinesthetic Learning: Cyclic Voltammetry Mechanisms Created by Chip Nataro, Lafayette College (nataroc@lafayette.edu) and posted on VIPEr (www.ionicviper.org) on July 6, 2015, Copyright Chip Nataro 2015. This work is licensed under the Creative Commons Attribution Non-commercial Share Alike License. To view a copy of this license visit http://creativecommons.org/about/license/.   -Chip Nataro Department of Chemistry Lafayette College

Electrochemical Mechanisms Chemically and electrochemically reversible Get 6 people to stand in a line. Walk down the line shaking hands (use of a joy buzzer is highly recommended but not required). Turn around. Go back through the line and shake hands again.

Cyclic Voltammogram Potential (V vs. FcH0/+) 0.20 0.10 0.00 -0.10 Start at some potential (everyone in a line wondering what I am going to do) Change potential (walking through the line) Current change (people annoyed with me as they got buzzed) Switching potential (turn around) Scan potentials (walk through the line) Change current (apologize for joy buzzer and everyone is happy) 1 mA 0.20 0.10 0.00 -0.10 -0.20 -0.30 -0.40 -0.50 -0.60 Potential (V vs. FcH0/+)

Electrochemical Mechanisms Chemically and electrochemically reversible Chemically irreversible Activity – Get 6 people to stand in a line. Walk down the line shaking hands. Turn around. Go back through the line but have them put their hands behind their backs. Second option, have them grab their neighbor’s hand after I shake theirs.

Cyclic Voltammogram ? Insert Figure 4 from this paper (doi:10.1016/S0022-328X(03)00155-4) The ? means that the product is unknown. Going through the line and shaking hands represents oxidation. The students in the line then make it so they can’t shake hands, perhaps by putting their hands behind their backs or linking hands with another student in line. This signifies the compound undergoing some kind of chemical reaction following oxidation and the resulting product is not electro-active. C. Nataro, A.N. Campbell, M.A. Ferguson, C.D. Incarvito, A.L. Rheingold, J. Organomet. Chem. 2003, 673, 47.

Electrochemical Mechanisms Chemically and electrochemically reversible Chemically irreversible Chemically reversible Activity – Get 6 people to stand in a line. Walk down the line shaking hands. Turn around. Go back through the line but have the middle two join hands.

Cyclic Voltammograms ? Insert Figure 1 from this paper (doi:10.1016/S0022-328X(03)00155-4) Again, the ? represents an unknown chemical species. Go through the line quickly and shake hands in both directions. This represents a fast scan rate which is quicker than a chemical reaction can occur after oxidation. The second time, go through the line slowly. Have some of the students do something (put their hands behind their backs or grab the hands of other students) so that they are unable to shake hands on the return pass. This indicates that the chemical reaction after oxidation is slow, so only some of the species are able to react. C. Nataro, A.N. Campbell, M.A. Ferguson, C.D. Incarvito, A.L. Rheingold, J. Organomet. Chem. 2003, 673, 47.

Electrochemical Mechanisms Chemically and electrochemically reversible Chemically irreversible Chemically reversible Quasi-reversible Activity – Get 6 people to stand in a line. Walk down the line shaking hands. Turn around. Go back through the line high five people instead. Having a significant height difference between the molecules and the potential can help here.

Cyclic Voltammogram Insert Figure 2 from this paper (doi:10.1021/om050074p) Pass through the students shaking hands. After shaking hands the students raise their hands in the air. On the return pass, you high five the students. This represents the compound being oxidized and going to a new species that is electroactive. It is just different. F.N. Blanco, L.E. Hagopian, W.R. McNamara, J.A. Golen, A.L. Rheingold, C. Nataro, Organometallics 2006, 25, 4292.