Linear MgCp*2 vs Bent CaCp*2 : London Dispersion, Ligand-Induced Charge Localizations, and Pseudo-Pregostic C–H···Ca Interactions

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 (2018). Linear MgCp*2 vs Bent CaCp*2 : London Dispersion, Ligand-Induced Charge Localizations, and Pseudo-Pregostic C–H···Ca Interactions. Inorganic chemistry, 57(9), pp. 4906-4920. American Chemical Society 10.1021/acs.inorgchem.7b03079

[img] Text
052_Pal2018_InorgChem.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (5MB) | Request a copy

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.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

Grabowsky, Simon

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

0020-1669

Publisher:

American Chemical Society

Language:

English

Submitter:

Simon Grabowsky

Date Deposited:

06 Feb 2020 11:14

Last Modified:

06 Feb 2020 11:14

Publisher DOI:

10.1021/acs.inorgchem.7b03079

BORIS DOI:

10.7892/boris.138414

URI:

https://boris.unibe.ch/id/eprint/138414

Actions (login required)

Edit item Edit item
Provide Feedback