EPR, ENDOR AND TRIPLE-RESONANCE OF AMINO-SUBSTITUTED 9,10-ANTHRAQUINONE RADICALS AND THE ROTATION OF THE AMINO-GROUPS IN THE SOLUTION-PHASE

EPR, ENDOR and TRIPLE resonance spectra were recorded for 1-amino-9,10 -anthraquinone (1-aminoAQ), 2-aminoAQ, 1,2-diaminoAQ, 1,4-diaminoAQ, 1 ,5-diaminoAQ and 2,6-diaminoAQ anion radicals in the solution phase, T he rotation of the amino groups is discussed with reference to the exp erimental data. Rotation barrier calculations were carried out using B 3PW91/3-21G density functional method. The amino groups at positions 1, 4, 5, 8 were found not to be in rotational movement up to the EPR t ime-scale.