The Application of Magnetic Circular Dichroism to the Study of the Tautomerism of Cytosine and Isocytosine

Abstract

Abstract The MCD and absorption spectra of cytosine and isocytosine and their N-substituted derivatives were measured in the wave-number region of 30000–50000 cm−1. On the basis of the experimental results, the tautomerism of cytosine and isocytosine was discussed. The transition energies, the oscillator strengths, and the Faraday B terms of the tautomeric forms of cytosine and isocytosine were calculated within the framework of the intermediate neglect of the differential overlap(INDO) approximation. The calculated results are in good agreement with the experimental data.