Hole interactions of aerogen oxides with Lewis bases: an insight into -hole and lone-pair-hole interactions

sigma-Hole and lone-pair (lp)-hole interactions of aerogen oxides with Lewis bases (LB) were comparatively inspected in terms of quantum mechanics calculations. The ZO(n) & ctdot; LB complexes (where Z = Kr and Xe, n = 1, 2, 3 and 4, and LB = NH3 and NCH) showed favourable negative interaction energies. The complexation features were explained in light of sigma-hole and lp-hole interactions within optimum distances lower than the sum of the respective van der Waals radii. The emerging findings outlined that sigma-hole interaction energies generally enhanced according to the following order: KrO4 & ctdot; < KrO & ctdot; < KrO3 & ctdot; < KrO2 & ctdot;LB and XeO4 & ctdot; < XeO & ctdot; < XeO2 & ctdot; < XeO3 & ctdot;LB complexes with values ranging from -2.23 to -12.84 kcal mol(-1). Lp-hole interactions with values up to -5.91 kcal mol(-1) were shown. Symmetry-adapted perturbation theory findings revealed the significant contributions of electrostatic forces accounting for 50-65% of the total attractive forces within most of the ZO(n)& ctdot;LB complexes. The obtained observations would be useful for the understanding of hole interactions, particularly for the aerogen oxides, with application in supramolecular chemistry and crystal engineering.