eta(5)– and eta(6)–Coordinations Revisited: An ELF Study of Ferrocene and Dibenzenechromium

Gilles Frison (1) , Alain Sevin (1)

1 LCT - Laboratoire de chimie théorique

Motivation. The chemistry of five–membered and six–membered conjugated cyclic ligands complexes belongs to the most important classes of organometallic compounds. The determination of the precise nature of the metal–ligand bond is of great importance for the synthesis of new compounds and understanding of their reactivity. We propose here a topological ELF analysis of the metal–ligand interaction with a comparative model study of eta(5)– and eta(6)–coordination respectively in ferrocene and dibenzenechromium. Method. Electron Localization Function (ELF) offers a reliable measure of electron pairing and localization. An ELF calculation partitions molecular space in terms of attractors and basins. Each basin, located around an attractor, could be clearly identify into series, each of then having a precise significance (core, lone pair, two– center bond, three–center bond, ...). Results. This work shows that both eta(5)– and eta-6)–coordinations could be decomposed in a sum of eta(1)– and eta(2)–interactions, the latter being predominant. The bonding description is in agreement with the classical resonance scheme. Conclusions. The topological analysis of the ELF function provides a basis for interpreting and visualization of the bonding scheme in model sandwich molecules. Availability. TopMoD package is available free of charge at http://www.lct.jussieu.fr/silvi/topmod_english.html.

Mots clés: Density Functional Theory (DFT) calculations; metallocenes; sandwich compounds; bond theory; Ferrocene; Electron Localization Function (ELF); metal–ligand interaction

Domaines: Chimie théorique et/ou physique; Chimie de coordination

Gilles Frison, Alain Sevin. eta(5)– and eta(6)–Coordinations Revisited: An ELF Study of Ferrocene and Dibenzenechromium. Internet Electronic Journal of Molecular Design, 2004, 3 (5), pp.222-232. ⟨hal-00464100⟩