Details

Autor(en) / Beteiligte

• Sergeieva, Tetiana
• Demirer, T. Ilgin
• Wuttke, Axel
• Mata, Ricardo A
• Schäfer, André
• Linker, Gerrit-Jan
• Andrada, Diego M

Titel

Revisiting the origin of the bending in group 2 metallocenes AeCp (Ae = Be-Ba)

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2023-08, Vol.25 (3), p.2657-2667

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Metallocenes are well-established compounds in organometallic chemistry, and can exhibit either a coplanar structure or a bent structure according to the nature of the metal center (E) and the cyclopentadienyl ligands (Cp). Herein, we re-examine the chemical bonding to underline the origins of the geometry and stability observed experimentally. To this end, we have analysed a series of group 2 metallocenes [Ae(C 5 R 5 ) 2 ] (Ae = Be-Ba and R = H, Me, F, Cl, Br, and I) with a combination of computational methods, namely energy decomposition analysis (EDA), polarizability model (PM), and dispersion interaction densities (DIDs). Although the metal-ligand bonding nature is mainly an electrostatic interaction (65-78%), the covalent character is not negligible (33-22%). Notably, the heavier the metal center, the stronger the d-orbital interaction with a 50% contribution to the total covalent interaction. The dispersion interaction between the Cp ligands counts only for 1% of the interaction. Despite that orbital contributions become stronger for heavier metals, they never represent the energy main term. Instead, given the electrostatic nature of the metallocene bonds, we propose a model based on polarizability, which faithfully predicts the bending angle. Although dispersion interactions have a fair contribution to strengthen the bending angle, the polarizability plays a major role. Metallocenes are well-established compounds in organometallic chemistry, which can exhibit either a coplanar structure or a bent structure according to the nature of the metal center (E) and cyclopentadienyl ligands (Cp).