The role of intermolecular interactions of aromatic sandwich dimer ligands for the half-titanocene catalysts: Theoretical study

Abstract

Visualization of intermolecular interaction of half-titanocene complex modified by sandwich dimers. (a) reduced density gradient function (RDG); (b) dispersion point isosurface diagram of weak intermolecular interaction. • Ab initio calculations on the influences of intermolecular interactions in ligands on the half-titanocenes. • A set of model ligands and their sandwich dimers optimized at 12 levels of theory. • Suitability in various occasions explored based on statistical analyses. • Intermolecular interactions visualized by wave function analyses and correlational analyses after feature extraction. • Types and intermolecular interactions of ligands in affecting the conformation of catalysts was discussed. The successful design of an efficient half-titanocenes could strongly benefit from a conceptual understanding of how intermolecular forces lead to structure formation on the atomistic level. This work reports density functional theory calculations on the influences of intermolecular interactions in aromatic ligands on the half-titanocenes. For this purpose, a set of model aromatic ligands R, in which R = benzene, naphthalene, anthracene, pyrene, hexafluorobenzene and their sandwich dimers, were chosen and optimized at 12 levels of theory including three kinds of hybrid functionals with different contents of HF functions combined with double or triple zeta basis sets with or without diffusion functions. The practicality and reliability of the assorted methods to predict geometric parameters were explored based on multivariable linear regression analysis and correlation analysis. Intermolecular interactions were visualized by wave function analyses and correlational analyses after feature extraction were conducted to discuss the possible role of types and intermolecular interactions of aromatic ligands in affecting the conformation of catalysts.