Exploring σ-hole bonding in XH3Si···HMY (X=H, F, CN; M=Be, Mg; Y=H, F, CH3) complexes: a "tetrel-hydride" interaction.

In this work, a σ-hole interaction is predicted theoretically in XH3Si···HMY complexes, where X=H, F, CN; M=Be, Mg and Y=H, F, CH3. The properties of this interaction, termed "tetrel-hydride" interaction, are investigated in terms of geometric, interaction energies, and electronic features of the complexes. The geometry of these complexes is obtained using the second-order Møller-Plesset perturbation theory (MP2) with aug-cc-pVTZ basis set. For each XH3Si···HMY complex, a tetrel-hydride bond is formed between the negatively charged H atom of HMY molecule and the positively charged Si atom of XH3Si molecule. The CCSD(T)/aug-cc-pVTZ interaction energies of this type of σ-hole bonding range from -0.6 to -3.8 kcal mol(-1). The stability of XH3Si···HMY complexes is attributed mainly to electrostatic and correlation effects. The nature of tetrel-hydride interaction is analyzed with atoms in molecules (AIM) and natural bond orbital (NBO) theories.