1. Contribution from the School of Chemistry, The University of Birmingham, Edgbaston, B15 2TT, United Kingdom, School of Chemistry, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, EH9 3JJ, United Kingdom, and Molecular Photonic Materials, Institute of Molecular Chemistry, Faculty of Science, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WS Amsterdam, The Netherlands