TY - JOUR
T1 - Revisiting the origin of the bending in group 2 metallocenes AeCp (Ae = Be–Ba)
AU - Sergeieva, Tetiana
AU - Demirer, T. Ilgin
AU - Wuttke, Axel
AU - Mata, Ricardo A.
AU - Schäfer, André
AU - Linker, Gerrit-jan
AU - Andrada, Diego M.
N1 - Funding Information:
D. M. A. and A. S. thank Prof. Dr David Scheschkewitz, Prof. Dr Guido Kickelbick and Saarland University for support. D. M. A., T. S. and T. I. D. thank the European Research Council, ERC, (ERC Starting grants, EU805113) for funding. A. S. thanks the Deutsche Forschungsgemeinschaft, DFG, (Emmy Noether-program, SCHA1915/3-1/2) for funding. G.-J. L. thanks Prof. Dr Piet Th. van Duijnen for support.
Publisher Copyright:
© 2023 The Royal Society of Chemistry.
PY - 2023/8/2
Y1 - 2023/8/2
N2 - 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(C5R5)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.
AB - 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(C5R5)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.
KW - UT-Hybrid-D
U2 - 10.1039/D2CP05020J
DO - 10.1039/D2CP05020J
M3 - Article
SN - 1463-9076
VL - 25
SP - 20657
EP - 20667
JO - Physical chemistry chemical physics
JF - Physical chemistry chemical physics
IS - 30
ER -