Electrografting of Mono-N-Boc-Ethylenediamine from an Acetonitrile/Aqueous NaHCO₃ Mixture

Authors

Hamzah Hisham, Chemistry, University of Southampton, Southampton, SO171AL, UK;
Denuault Guy, Chemistry, University of Southampton, Southampton, SO171AL, UK;
Bartlett Philip, Chemistry, University of Southampton, Southampton, SO171AL, UK;Follow
Pinczewska Aleksandra, School of Biological and Chemical Sciences Queen Mary University of London, Mile End Road, London, E1 4NS, UK;
Kilburn Jeremy, King’s College, The University of Aberdeen, Aberdeen, AB24 3FX, UK

Corresponding Author

Bartlett Philip(p.n.bartlett@soton.ac.uk)

Abstract

The electrografting of primary amines to carbon electrodes is now widely employed for electrode modification. Using a mixture of acetonitrile and 0.1 mol•L^-1 aqueous sodium hydrogen carborate (NaHCO₃) in the ratio of 4:1, the efficiency for coupling of mono-N-Boc-ethylenediamine (EDA-Boc) on the surface of glassy carbon was significantly improved as compared with that obtained using acetonitrile alone. In the presence of NaHCO₃ the initial current determined in the cyclic voltammogram became higher, and the layer of attached amine was formed more rapidly, accordingly, the electrode was passivated more rapidly. The resulting film of EDA-Boc was shown to be more severely blocking toward the electrochemical reaction of [Fe(CN)₆]^3-. Following removal of the Boc protecting group and coupling of the free amine to anthraquinone-2-carboxylic acid, a higher surface coverage of the anthraquinone was obtained. Modelling for the electrograftng reaction using a simple kinetic scheme, it was demonstrated that the simulated voltammograms agreed well with the experimentally measured voltammograms . Comparison between the model fitting parameters obtained from the acetonitrile alone and the acetonitrile/NaHCO₃ mixture showed that the competition between reaction of the amine radicals with the carbon surface and reaction in the homogeneous solution became more favourable for the surface reaction in the acetonitrile/NaHCO₃ mixture.

Graphical Abstract

DOI Link

https://doi.org/10.13208/j.electrochem.161241

Publication Date

2017-04-28

Online Available Date

2017-01-29

Revised Date

2017-01-21

Received Date

2016-12-01

Recommended Citation

Hamzah Hisham, Denuault Guy, Bartlett Philip, Pinczewska Aleksandra, Kilburn Jeremy. Electrografting of Mono-N-Boc-Ethylenediamine from an Acetonitrile/Aqueous NaHCO₃ Mixture[J]. Journal of Electrochemistry, 2017 , 23(2): 161241.
DOI: 10.13208/j.electrochem.161241
Available at: https://jelectrochem.xmu.edu.cn/journal/vol23/iss2/15