Intramolecular electron transfer has been investigated for three diphenyletioporphyrins covalently linked to an anthraquinone via a sulfonyloxy bridge at the ortho, meta or para substitution position of the phenyl groups of the porphyrin. The ortho-linked porphyrin is strongly folded and exhibits extremely fast charge separation (CS) and recombination (CR) between porphyrin and anthraquinone (kCS > 3 × 1011 s-1 and kCR = 5.9 × 1010 s-1 in CH2Cl2). The less-folded meta- and para-linked porphyrins have smaller electron transfer rate constants. For the ortho-linked compound in toluene a biphasic charge separation is observed. The triplet state is formed in high yield via fast intersystem crossing in the charge-separated state.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry