Metal-involved C⋯dz2-PtII tetrel bonding as a principal component of the stacking interaction between arenes and the platinum(ii) square-plane

Abstract

The half-lantern Pt^II₂ complexes [Pt(C^∩N)(μ-S^∩N)]₂ (C^∩N = 2-naphtylbenzothiazolate 1; 2-phenylbenzothiazolate 2; S^∩N = 2-thiopyridine) were crystallized with electron-deficient arenes such as hexafluorobenzene (C₆F₆) and octafluoroanthraquinone (OFA) to furnish cocrystals 1·C₆F₆, 2·C₆F₆, and 1·(OFA)₂, all studied by X-ray crystallography. The obtained structural data revealed that structure-determining π–π stacking occurred between the arenes and metal square-planes. Density functional theory calculations, employing a set of computational tools, verified the contribution of the C⋯d_z²-Pt^II noncovalent bond in the overall stacking forces. Orbital interaction analysis using the charge displacement function (CDF) combined with the extended transition state natural orbital for chemical valence theory (ETS-NOCV) method demonstrated the significance of the d_z²(Pt) → π*(C) charge-transfer interaction, which allows the attribution of the C⋯Pt contact to a metal-involved tetrel bonding. Many-body interaction analysis demonstrates a positive cooperative effect between the fragments of the half-lantern complex and the perfluoroarenes favoring the occurrence of supramolecular chains.