Bonding Situation of σ-E-H Complexes in Transition Metal and Main Group Compounds

The ambiguous bonding situation of sigma-E-H (E=Si, B) complexes in transition metal compounds has been rationalized by means of Density Functional Theory calculations. To this end, the combination of the Energy Decomposition Analysis (EDA) method and its Natural Orbital for Chemical Valance (NOCV) extension has been applied to representative complexes described in the literature where the possible eta(1) versus eta(2) coordination mode is not unambiguously defined. Our quantitative analyses, which complement previous data based on the application of the Quantum Theory of Atoms in Molecules (QTAIM) approach, indicate that there exists a continuum between genuine eta(1) and eta(2) modes depending mainly on the strength of the backdonation. Finally, we also applied this EDA-NOCV approach to related main-group species where the backdonation is minimal.

Automated summary

The bonding situation of sigma-E-H (E=Si, B) complexes in transition metal compounds has been studied using Density Functional Theory calculations. It was found that the coordination mode between eta(1) and eta(2) is ambiguous and depends on the strength of the backdonation. This study provides a new quantitative analysis method for understanding the bonding behavior of transition metal compounds.