Synthesis and Hydrogen-Bond Patterns of Aryl-Group Substituted Silanediols and -triols from Alkoxy- and Chlorosilanes

Organosilanols typically show a high condensation tendency and only exist as stable isolable molecules under very specific steric and electronic conditions at the silicon atom. In the present work, various novel representatives of this class of compounds were synthesized by hydrolysis of alkoxy- or chlorosilanes. Phenyl, 1-naphthyl, and 9-phenanthrenyl substituents at the silicon atom were applied to systematically study the influence of the aromatic substituents on the structure and reactivity of the compounds. Chemical shifts in Si-29 NMR spectroscopy in solution, correlated well with the expected electronic situation induced by the substitution pattern on the Si atom. H-1 NMR studies allowed the detection of strong intermolecular hydrogen bonds. Single-crystal X-ray structures of the alkoxides and the chlorosilanes are dominated by pi-pi interactions of the aromatic systems, which are substituted by strong hydrogen bonding interactions representing various structural motifs in the respective silanol structures.

Automated summary

Novel representatives of organosilanols were synthesized in this study by hydrolysis of alkoxy- or chlorosilanes, with aromatic substituents applied to study their structure and reactivity. Si-29 NMR and H-1 NMR spectroscopy revealed electronic situations induced by substitution patterns and strong intermolecular hydrogen bonds, while X-ray crystallography showed interactions between aromatic systems and hydrogen bonding in silanol structures.