Abstract

Recently it had been shown that ultrafast electron transfer (ET) reactions can occur even faster than relevant reorganisation and relaxation processes /1-3/. These experiments raised a number of new questions such as: How can those ultrafast reactions proceed, what reaction mechanism applies and what is the role of specific vibrational modes or wavepacket motions? In this paper we present new experimental results taken over a wide range of probing wavelengths with highest time resolution on a fast ET-system. We will focus on the system oxazine 1 in two solvents: The first combination is oxazine 1 (OX1) in dimethylaniline (DMA) where an ultrafast light induced ET occurs from DMA to OX1. As a reference system without electron transfer, we use the solvent 1-chloronaphtalene (1-CN) which has similar solvent properties ( dipole moment, dielectric constant, viscosity) as dimethylaniline. The experiments are performed with a CPM-laser based amplifier/compressor system /4/ with red (630 nm) excitation and different probing wavelengths covering the whole visible spectrum. Cross-correlation widths are ≈12 fs in the red and near IR and ≤ 22 fs in the blue-green part of the spectrum.

© 1996 Optical Society of America