a
Institute of Inorganic Chemistry, Christian-Albrechts-Universität Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany
E-mail: stock@ac.uni-kiel.de
b
Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Kraków, Poland
c
Inorganic Chemistry I, Universität Bayreuth, Universitätsstaße 30, 95447 Bayreuth, Germany