STRUCTURE AND ESR FEATURES OF GLYCINE RADICAL IN ITS ZWITTERIONIC FORM

Extensive post Hartree-Fock calculations are reported for the geometri cal structure and hyperfine parameters of the carbon-centered glycine radical in its zwitterionic form. Vibrational averaging effects connec ted to inversion at the radical center are significant for C-alpha and H-alpha atoms. The good agreement between computed and experimental h yperfine splittings confirms the nature of one of the radicals obtaine d from irradiation of glycine crystals. On the other hand, the ESR spe ctrum obtained in aqueous solution cannot be due to the zwitterionic f orm.