%0 Journal Article %A Mohammed, Omar F. %A Adamczyk, Katrin %A Banerji, Natalie %A Dreyer, Jens %A Lang, Bernhard %A Nibbering, Erik T.J. %A Vauthey, Eric %T Direct Femtosecond Observation of Tight and Loose Ion Pairs upon Photoinduced Bimolecular Electron Transfer %J Angewandte Chemie International Edition %@ 1433-7851 %V 47 %N 47 %P 9044-9048 %D 2008 %U http://www3.interscience.wiley.com/journal/121460010/abstract %R 10.1002/anie.200803164 %U http://archive-ouverte.unige.ch/unige:3182 %X Polarization-sensitive ultrafast infrared measurements on photoinduced electron transfer in donor-acceptor pairs in polar acetonitrile show distinct contributions from loose and tight ion pairs. Highly anisotropic signals from tight ion pairs reveal the importance of mutual orientation of the reactants (see picture) and thus the need to refine theoretical models based on spherical species that solely involve reaction distances.