Journal of Electroanalytical Chemistry, Vol.686, 54-57, 2012
Comparison of diffusivities data of streptocyanine dyes by electrochemical and NMR-DOSY methods
Diffusivity data of streptocyanine dyes in acetonitrile were investigated using both transient voltammetric techniques and NMR-DOSY. Results of voltammetric measurements allow determination of the diffusion coefficient D values in the range of 1.2-1.6 x 10(-9) m(2) s(-1) the target dyes. Deuterated acetonitrile solvent was used for NMR-DOSY experiments and diffusivities of streptocyanines are given after calibration of acetonitrile on its tracer diffusion value of D*(ACN) of 4.37 x 10(-9). The results for the two methods appear to be in good agreement allowing use of the convenient NMR-DOSY method to measure diffusivity of streptocyanine dyes at low concentrations and so giving a direct access to the number of exchanged electrons using limiting current electrochemical techniques. This last method affords a great advantage of obtaining diffusion coefficients by non-electrochemical method. (C) 2012 Elsevier B.V. All rights reserved.
Keywords:Diffusion coefficient;Self-diffusion;Mutual diffusion;Convolution potential sweep voltammetry;NMR-DOSY