1. Department of Health Sciences and Technology ETH Zürich Schmelzbergstrasse 9 8092 Zürich Switzerland
2. European Laboratory for Non-Linear Spectroscopy, LENS Via Nello Carrara 1 50019 Florence Italy
3. Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
4. Department of Chemistry University of Perugia Via Elce di Sotto 8 06123 Perugia Italy
5. Department of Materials ETH Zürich Wolfgang-Pauli-Strasse 10 8093 Zürich Switzerland