| Autor: |
Pal, Rumpa, Mebs, Stefan, Shi, Ming W., Jayatilaka, Dylan, Krzeszczakowska, Joanna M., Malaspina, Lorraine A., Wiecko, Michal, Luger, Peter, Hesse, Malte, Chen, Yu-Sheng, Beckmann, Jens, Grabowsky, Simon |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
|
| DOI: |
10.7892/boris.138414 |
| Popis: |
In the family of metallocenes, MgCp*2 (Cp* = pentamethylcyclopentadienyl) exhibits a regular linear sandwich structure, whereas CaCp*2 is bent in both the gas phase and solid state. Bending is typically observed for metal ions which possess a lone pair. Here, we investigate which electronic differences cause the bending in complexes lacking lone pairs at the metal atoms. The bent gas-phase geometry of CaCp*2 suggests that the bending must have an intramolecular origin. Geometry optimizations with and without dispersion effects/d-type polarization functions on MCp2 and MCp*2 gas-phase complexes (M = Ca, Mg) establish that attractive methyl···methyl London dispersion interactions play a decisive role in the bending in CaCp*2. A sufficient polarizability of the metal to produce a shallow bending potential energy curve is a prerequisite but is not the reason for the bending. Concomitant ligand-induced charge concentrations and localizations at the metal atoms are studied in further detail, for which real-space bonding and orbital-based descriptors are used. Low-temperature crystal structures of MgCp*2 and CaCp*2 were determined which facilitated the identification and characterization of intermolecular pseudo-pregostic interactions, C–H···Ca, in the CaCp*2 crystal structure. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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