Three WVI crystal structures with multifarious bond types are used to theoretically predict the homolytic bond enthalpies with 11 popular DFT functionals, MP2 wavefunction methods, and 4 common valence basis set/pseudopotentials to evaluate the accuracy and precision of the resultant bond enthalpy data. For perhaps the first time, quantified estimates of component metal-ligand σ and π bonds are broken-down. The WE (W = C, N, O) bonds have the consistent trend σ &gt; 2nd π &gt; 1st π for bond strength. In contrast, the trend for the 2p nonmetal molecule homologs follow the trend of 2nd π &gt; 1st π &gt; σ for nitrogen and oxygen, and σ &gt; 1st π &gt; 2nd π for carbon. This difference may underpin the differences in stability trends and thus reactivity behavior for metal-element multiple bonds as compared to the element-element multiple bonds. For example, Odom et al. show that MeI nucleophilically attacks at the imide rather than the nitride ligand; the relative π-bond strengths derived herein provide a thermodynamic rationalization for this site preference. In this study, it is deduced that the W-oxo ligand is more congruous with a triple bond than a double bond, consistent with Harry Gray’s famous Oxo Wall.

Tungsten-ligand bond strengths for 2p elements, a DFT and ab initio study

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.