THE FIRST OBSERVATION OF CIDEP GENERATED THROUGH THE INTERACTION BETWEEN AN EXCITED SINGLET OXYGEN MOLECULE AND A FREE-RADICAL

Chemically induced dynamic electron polarization (CIDEP) generated thr ough the interaction between the lowest excited singlet oxygen molecul e and 2,2,6,6,-tetramethylpiperidinyl-1-oxyl (TEMPO) radical was obser ved by the time-resolved ESR technique. Excited singlet oxygen molecul es were produced by the triplet sensitizer through energy transfer. Ab sorptive electron spin polarization was generated on the free radical in the excited singlet oxygen molecule - free radical system, in which the CIDEP generation was interpreted by the radical-triplet pair mech anism with doublet precursor (DP-RTPM). The CIDEP time profile was suc cessfully analyzed by using the Bloch equations. Quenching of O-1(2) b y beta-carotene provides further evidence for DP-RTPM in the O-1(2)-TE MPO system.