Formation of C₆₀-SnI₄ adducts. Insights of the role of σ-hole and tetrel-bonding in the strength and interaction nature from DFT calculations

C₆₀-SnI₄ cocrystals expose the ability of highly symmetric units to form chiral materials. Here, we explore the underlying characteristics accounting for the stabilization of the C₆₀•••SnI₄ interaction within the framework of relativistic dispersion-corrected DFT calculations. Our results explore different interaction modes ranging from a purely σ -bond to tetrel-bond for C₆₀•••SnI₄ denoting the larger contribution from London-type interaction being more relevant than the electrostatic character inherent to σ-hole interactions, owing to the presence of iodine atoms. The resulting aggregate is further evaluated owing to its structural flexibility given by different noncovalent interaction modes based on both σ -hole and tetrel-bonding characteristics of SnI₄. Hence, it is proposed that C₆₀-SnI₄ cocrystals can be further modified under compression undergoing different phase transitions, leading to further exploration of crystal characteristics and versatility, which may be extended to other interesting π-systems. In addition, C₆₀-EX₄ (E = C, Si, Ge, Sn, Pb; X = Cl, Br, I) series are given, showing similar stabilizing characteristics, increasing towards heavier elements, denoting the C₆₀-PbI₄ cocrystal as a noteworthy case with stronger noncovalent interactions, which is here encouraged for further explorations.