Mutual interplay between pnicogen–π and tetrel bond in PF3⊥X–Pyr…SiH3CN complexes: NMR, SAPT, AIM, NBO, and MEP analysis

Abstract

The mutual interplay between pnicogen–π and tetrel bond in the formation of PF3⊥X–Pyr…SiH3CN ternary complexes has been investigated via a computational chemistry at MP2/aug-cc-pVDZ level of theory. We proved by computational NMR data the effect of electron-withdrawing and electron-donating substituents on 1tJ(N-Si) across 15N...35Si tetrel bonds was investigated at M06-2X/aug-cc-pVDZ levels of theory in PF3⊥CN–Pyr…SiH3CN complex. The nature of the interactions has been studied by means of symmetry-adapted perturbation theory (SAPT) and molecular electrostatic potentials (MEP). The electrostatic interaction played a major role in the change of tetrel bond interaction strength in the X–Pyr…SiH3CN binary systems, whereas the change of pnicogen–π strength in the PF3⊥X–Pyr complexes was caused jointly by the dispersion interactions. Energy decomposition indicates that the percentage of the electrostatic term in the tetrel bond system constitutes in the total attractive binding energies, while the percentage of the dispersion term in the pnicogen bonding constitutes in the attractive binding energies. In addition, atoms in molecules (AIM) and natural bond orbital (NBO) analyses were also performed to unveil the mechanism of these interactions in the title complexes.