The internal reorganization energy (λV) of photoinduced electron transfer (ET) in the supramolecular donor-acceptor dyads of 2,3,7,8,12,13,17,18-octaethylporphinatozinc(II) (ZnOEP) and electron acceptor ligands was compared with those of structural isomers, 2,3,7,8,11,12,17,18- octaethylhemiporphycenatozinc(II) (ZnHPc) and 2,3,6,7,12,13,16,17- octaethylporphycenatozinc(II) (ZnPcn). First, ET process of the supramolecular donor-acceptor dyads of ZnOEP was investigated by means of the transient absorption spectroscopy mainly. The formation of supramolecular dyads was confirmed by absorption spectral change, from which the association constant was estimated. The ET process was confirmed by the observation of radical cation of ZnOEP during the laser flash photolysis. The ET rates of these dyads are in the order of ZnOEP > ZnHPc > ZnPcn, when the driving forces for ET are similar to each other. From the free energy dependence of ET rates, the λV values of OEP and its isomers were estimated. The estimated λV value was in the order of ZnOEP < ZnHPc < ZnPcn. This tendency was reproduced by calculation at B3LYP/6-31G(d) and BHandHLYP/6-31G(d) levels. The origin of this tendency was discussed on the basis of the structural change during the ET process.
|Number of pages||7|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|Publication status||Published - Jan 1 2011|
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Physics and Astronomy(all)