The intermolecular interactions were analyzed by the time-resolved EPR technique for crown ether substituted porphyrins and phthalocyanines. The contributions of charge resonance-type(CR) and exciton-type(EX) interactions were directly estimated on the basis of the zero field splitting parameters, D, of the excited triplet (T1) states of the monomers and their crown ether bridged dimers. In the case of T1 porphyrin, 3(a2u, eg), it was found that the central metal(Zn) plays an important role on the interplanar interaction in contrast to a small effect observed in T1, phthalocyanine, 3(a1u, eg). These results are interpreted in terms of the interaction between the 4pz orbital of Zn and a2u of porphyrin. The magnitude of CR contribution is correlated well with those of the red shifts in the lowest excited singlet and triplet states of the dimers.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry