The UV-vis absorption, MCD and fluorescence spectra of phthalocyaninatosilicon (SiPc) covalently linked to one or two TEMPO radicals have been studied in comparison with those of (dihydroxy)SiPc. The electronic absorption and MCD spectra show little change on substitution of TEMPO radicals, indicating that the electronic interaction between excited singlet SiPc (1SiPc*) and doublet TEMPO (2TEMPO) is very weak or non-existent. In contrast, fluorescence quantum yields decrease markedly with increasing number of TEMPO radicals. This result is interpreted reasonably by assuming that the decay from 1SiPc* to excited triplet SiPc (3SiPc*) partially becomes a spin-allowed transition owing to the interaction between 3SiPc* and 2TEMPO.
|Number of pages||5|
|Journal||Journal of Porphyrins and Phthalocyanines|
|Publication status||Published - 1999|
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