Masaaki Mitsui (Kyoto Univ.), Keizo TAKEDA (IBM), Yasuhiro Kobori (Tohoku Univ.), Akio Kawai (Tokyo Inst. Tech.) and Kinichi Obi (Tokyo Inst. Tech. and IMS)
[Chem. Phys. Lett. 262, 125 (1996)]
CIDEP generated through the interaction between the lowest excited singlet oxygen molecule and 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) radical was observed by time-resolved ESR technique. Excited singlet oxygen molecules were produced by the triplet sensitized reaction. Absorptive 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 mechanism with doublet precursor (DP-RTPM). The CIDEP time profile was successfully analyzed by using the Bloch equations. Quenching of singlet oxygen with (beta)-carotene provides further evidence for DP-RTPM in the 1O2-TEMPO system.