Cooperation of Peripheral Hydrogen Atoms for the Stabilization of Aachno-pentaborane (11) with Small Molecules: Hydrogen Bonds and Dihydrogen Bonds

Abstract

Post-Hartree-Fock calculations performed at the MP2/aug-cc-pVDZ level of theory has been used to analyze the formation of intermolecular complexes between B₅H₁₁ and W = CO, NCH, NH₃, H₂O or HOCH₃. The interactions on the structure of the arachno-pentaborane(11) are manifested by the terminal and bridge hydrogen atoms, whereby are formed the hydrogen bonds (H∙∙∙Y with Y = O, C or N) as well as dihydrogen bonds (H∙∙∙H). In this context, the B₅H₁₁ shows a host-guest capability for trapping molecules, of course depending on the strength of each aforementioned interactions. The topological descriptors of the Quantum Theory of Atoms in Molecules (QTAIM) were decisive for unveiling each one of the following structures B₅H₁₁∙∙∙CO, B₅H₁₁∙∙∙NCH, B₅H₁₁∙∙∙NH₃, B₅H₁₁∙∙∙H₂O and B5H₁₁∙∙∙HOCH₃, and ideally, all hydrogen bonding formed by them.