1. Contribution from the Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands, Laboratory of Molecular Physics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands, Akzo Nobel Central Research, Velperweg 76, 6800 SM Arnhem, The Netherlands, and Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands