1. Institute
of Physics, Johannes Gutenberg University Mainz, Staudingerweg
7, D-55099 Mainz, Germany
2. Department
of Chemistry, Graduate School of Science, Kyoto University, Sakyoku, Kyoto 606-8502, Japan
3. Department
for Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany