Interactions in Model Ionic Dyads and Triads Containing Tetrel Atoms.

The interactions in model ionic YTX···Z (Y = NC, F, Cl, Br; X = F, Cl, Br, Z = F, Cl, Br, Li) dyads containing the tetrel atoms, T = C, Si, Ge, were studied using ab initio computational methods, including an energy decomposition analysis, which found that the YTX molecules were stabilized by both anions (via tetrel bonding) and cations (via polarization). For the tetrel-bonded dyads, both the electrostatic and polarization forces make comparable contributions to the binding in the C-containing dyads, whereas, electrostatic forces are by far the largest contributor to the binding in the Si- and Ge-containing analogues. Model metastable Li···NCTCl···F (T = C, Si, Ge) triads were found to be lower in energy than the combined energy of the Li + NCTCl + F fragments. The pair energies and cooperative energies for these highly polar triads were also computed and discussed.