Affiliation:
1. Mulliken Center for Theoretical Chemistry University of Bonn Beringstraße 4 53115 Bonn Germany
2. Institut für Anorganische und Analytische Chemie Goethe-Universität Frankfurt am Main Max-von-Laue-Straße 7 60438 Frankfurt am Main Germany
3. Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
Abstract
AbstractA joint theoretical and experimental study on 32 endohedral silafullerane derivatives [X@Si20Y20]− (X=F‐I; Y=F‐I, H, Me, Et) and
‐[Cl@Si20H12Y8]− (Y=F‐I) is presented. First, we evaluated the structure‐determining template effect of Cl− in a systematic series of concave silapolyquinane model systems. Second, we investigated the X−→Si20 interaction energy (
) as a function of X− and Y and found the largest
values for electron‐withdrawing exohedral substituents Y. Given that X− ions can be considered as Lewis bases and empty Si20Y20 clusters as Lewis acids, we classify our inseparable host–guest complexes [X@Si20Y20]− as “confined Lewis pairs”. Third, 35Cl NMR spectroscopy proved to be highly diagnostic for an experimental assessment of the Cl−→Si20 interaction as the paramagnetic shielding and, in turn,
(35Cl) of the endohedral Cl− ion correlate inversely with
. Finally, we disclose the synthesis of [PPN][Cl@Si20Y20] (Y=Me, Et, Br) and provide a thorough characterization of these new silafulleranes.
Funder
Fonds der Chemischen Industrie
Deutsche Forschungsgemeinschaft
Max-Planck-Gesellschaft