Enantioanalysis of R-deprenyl based on its molecular interaction with C70 fullerenes

Two enantioselective, potentiometric membrane electrodes based on [5,6]fullerene-C70 (1) and diethyl (1,2-methanofullerene C70)-71-71-dicarboxylate (2) immobilized in carbon paste, were designed for the enantioanalysis of R-deprenyl. The electrodes exhibited near-Nernstian slopes: 57.90 (1) and 59.00 mV/decade of concentration (2), respectively with low limits of detection 5.9 × 10−11 (1) and 9.6 × 10−11 mol/L (2), respectively. The linear concentration ranges are between 10−10 and 10−4 mol/L (1) and between 10−9 and 10−4 mol/L (2), respectively. The different characteristics involved in the molecular interaction between R-deprenyl and C70 fullerenes were explained, namely (i) the stability of each molecule and (ii) the explanation of the molecular mechanism of interaction, using restricted Hartree–Fock theory, 3-21G(*) RHF-basis set. Furthermore, two intermolecular forces of interactions confer the stability of the electrodes; electrostatic interaction and moderate hydrogen bond interaction. Stability and feasibility of all the generated structures involved in this analysis were supported by their respective fundamental frequencies and energy minima. enyl can be recovered with average recoveries higher than 99.10% (RSD < 0.03%) from synthetic mixtures between R- and S-deprenyl. The high selectivity and enantioselectivity made possible the enantioanalysis of R-deprenyl in its pharmaceutical formulations.