Photo-induced intramolecular electron transfer(PIET) and intramolecular vibrational relaxation(IVR) dynamics of the excited state of rhodamine 6G(Rh6G+) in DMSO are investigated by multiplex transient grating. Two major components are resolved in the dynamics of Rh6G+. The first component, with a lifetime τPIET = 140 fs–260 fs, is attributed to PIET from the phenyl ring to the xanthene plane. The IVR process occurring in the range τIVR = 3.3 ps–5.2 ps is much slower than the first component. The PIET and IVR processes occurring in the excited state of Rh6G+are quantitatively determined, and a better understanding of the relationship between these processes is obtained.
