Empirical calculations of 29Si NMR chemical shielding tensors: A partial charge model investigation of hydrolysis in organically modified alkoxy silanes

Abstract

The ²⁹Si NMR chemical shifts for a series of organically modified silane compounds, Me_xSi(OR)_y(OH)_{4 − x − y} (OR = OMe, OEt), were evaluated using a partial charge model (PCM) approach to describe the chemical bonding. These PCM results allow the relative contributions of the diamagnetic and paramagnetic terms in the ²⁹Si NMR chemical shielding constant to be discussed. An explanation for the unique variations in the ²⁹Si chemical shifts during for hydrolyzed organically modified silanes is presented.