1. Molecular Electronics, Zernike Institute for Advanced Materials, Rijksuniversiteit
Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
2. Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven,
The Netherlands
3. Molecular
Materials and Nanosystems, Eindhoven University of Technology, P.O. Box 513, 5600
MB Eindhoven, The Netherlands