Electron transfer from poly(phenylmethylgermylene) (PMePhGe) to photoexcited C60in benzene—acetonitrile solution has been investigated by 532 nm laser flash photolysis in the near-IR region. The transient absorption band of the C60triplet state (3C60*) appeared immediately after nanosecond laser exposure. With the decay of 3C60*, the absorption bands of the radical anion of C60(C60 •-) and the radical cation of PMePhGe appeared in the region 900-1600 nm. The rate constant of the electron transfer from PMePhGe to 3C60* was determined to be 2.33 × 108 M-1 s-1, which was similar to that for poly(methylphenylsilylene). Electron transfer from the singlet state of C60(1C60*) was investigated by fluorescence quenching experiments using a picosecond fluorescence lifetime measurement system, and the quenching rate constant was determined to be 4.00 × 1010 M-1 s-1. The rate constant of intersystem crossing from 1C60* to 3C60* was determined to be 1.10 × 109 s-1 by picosecond time-resolved absorption spectroscopy using a streak camera. Electron transfer from 1C60* to PMePhGe and intersystem crossing from 1C60* to 3C60* are competitive, and the intersystem crossing is dominant in a dilute solution system. When a 355 nm laser was used as the excitation light, photochemical intermediates were produced from the direct photolysis of PMePhGe in addition to the electron transfer.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry