NMR and X-ray Studies of Hydrogen Bonding for Amide-Containing Silanediols

The synthesis, isolation, and hydrogen-bonding properties of a series of amide-containing silanediols are described, including an enantioenriched silanediol. By incorporation of a 2,4,6-trimethylphenyl (mesityl) group, these functionalized silanediols are isolable by column chromatography and stable in the presence of standard acids (e.g., AcOH) and bases (e.g., NH4OH). NMR spectroscopy and X-ray crystallography provide evidence for the conformational rigidity and binding properties of amido-silanediols based on the parameters (e.g., sterics, hybridization, and ring size of hydrogen bonding) that affect intra- and intermolecular hydrogen bonding. Pyridine binding studies demonstrate that these conformational effects have implications for the existence of single versus multiple modes of hydrogen bonding.