Comprehensive Insight into the Hydrogen Bonding of Silanes

The interaction of a set of mono-, di- and trisubstituted silanes with OH proton donors of different strength was studied by variable temperature (VT) FTIR and NMR spectroscopies at 190-298K. Two competing sites of proton donors coordination: SiH and -density of phenyl ringsare revealed for phenyl-containing silanes. The hydrogen bonds SiHHO and OH(Ph) are of similar strength, but can be distinguished in the (SiH) range: the (SiHHO) vibrations appear at lower frequencies while OH(Ph) complexes give Si-H vibrations shifted to higher frequency. The calculations showed the manifold picture of the noncovalent interactions in hydrogen-bonded complexes of phenylsilanes. As OHHSi bonds are weak, the other noncovalent interactions compete in the stabilization of the intermolecular complexes. Still, the structural and electronic parameters of pure DHB complexes of phenylsilanes are similar to those of Et3SiH.