The Detection and Reactivity of Silanols and Silanes Using Hyperpolarized 29 Si Nuclear Magnetic Resonance

Angew Chem Int Ed Engl. 2020 Feb 10;59(7):2710-2714. doi: 10.1002/anie.201915098. Epub 2020 Jan 9.

Abstract

Silanols and silanes are key precursors and intermediates for the synthesis of silicon-based materials. While their characterization and quantification by 29 Si NMR spectroscopy has received significant attention, it is a technique that is limited by the low natural abundance of 29 Si and its low sensitivity. Here, we describe a method using p-H2 to hyperpolarize 29 Si. The observed signal enhancements, approaching 3000-fold at 11.7 T, would take many days of measurement for comparable results under Boltzmann conditions. The resulting signals were exploited to monitor the rapid reaction of tris(tert-butoxy)silanol with triflic anhydride in a T1 -corrected process that allows for rapid quantification. These results demonstrate a novel route to quantify dynamic processes and intermediates in the synthesis of silicon materials.

Keywords: NMR spectroscopy; SABRE; catalysis; hyperpolarization; silicon.