Parameterization of Phosphine Ligands Modified Rh Complexes to Unravel Quantitative Structure-Activity Relationship and Mechanistic Pathways in Hydroformylation

This study has established the quantitative structure-activity relationship (QSAR) model to predict formaldehyde hydroformylation activity using a class of phosphine-Rh complexes and computational mechanistic pathway analysis. A group of computational parameters (e.g., cone angle, G-parameter, buried volume, CO vibration frequency, NBO charge, HOMO and LUMO energy, Rh P distance) describing the complex structural (e.g., steric and electronic) features were achieved for descriptor database of monodentate phosphine ligands. Mathematical modelling of the catalytic results with the descriptors via multivariate linear regression reveals the hydroformylation rate is principally under electronic control within the investigated ligands. Computational mechanistic analysis demonstrates significant impact of electronic feature on TOF-determining transition state/intermediate and energetic span. The H-2 distortion energy analysis elucidates the variation of energetic span of the transition states related to H-2 oxidation addition, rationally accounting for the reaction outcomes.