Multinuclear NMR and X-ray diffraction study of pentacoordinated siloxane structures derived of pyridine diols

Synthesis and characterization of hypervalent pentacoordinated organosilicon complexes obtained from the reaction of disubstituted pyridine ligands with dichlorodiphenylsilane, dichloromethylphenylsilane and bis(dimethylamino)dimethylsilane are reported. The monomeric complexes obtained were characterized by mass spectrometry and multinuclear NMR spectroscopy; additionally their structures were established by X-ray diffraction analysis. The structural parameters indicated Si-N interaction with pentacoordinated geometries displaced towards trigonal bipyramid (TBP); the ²⁹ Si-NMR data for these compounds are in agreement with the presence of N → Si bond. In addition to a variable temperature ¹H-NMR study was carried out showing a dynamic behavior for these compounds.