Popis: |
Taking into account the biological significance of electron-exchange properties of nucleic heterocycles, we have studied the electrochemical reduction of their simplest model compound i.e. the pyrimidine, using drop-time controlled polarography and cyclic voltammetry on mercury drop and stationary vitreous carbon electrode. The characteristics of the different reduction waves have been studied with respect to the different experimental parameters: pH, nature and concentration of buffer solutions, pyrimidine concentration, mercury flow and mechanically controlled drop-time, temperature, nature of the electrode, etc. The analysis of the experimental data is discussed in terms of energetical significance of the phenomena observed. Evidence is given of a chemical association step, possibly a dimerization, occuring between the two reduction steps in acid media. |