1. Contribution from the Department of Chemical Analysis, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, Department of Physical and Computational Chemistry, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, Department of Organic and Molecular Inorganic Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands, and Bijvoet Center for Biomolecular Research, Crystal and Structural Chemistry, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The...