Hans Kuhn, Dr. phil., (deceased) was Professor and Director of the Institute of Physical Chemistry at the Philipps-University of Marburg from 1953-1970. In 1970 he became Director at the Max Planck Institute for Biophysical Chemistry (Karl-Friedrich-Bonhoeffer-Institute) until he retired in 1985. He died in 2012. David H. Waldeck, Ph D, is Professor of Chemistry and Director of the Petersen Institute for Nanoscience and Engineering at the University of Pittsburgh. Horst-Dieter Försterling, Dr. phil., was Professor in the Department of Physical Chemistry at the Philipps-University of Marburg from 1972 until his retirement in 1999.