Resumen de Measurement of the Isotopic Ratio of 10B/11B in NaBH4 by 1H NMR

Murray Zanger, Guillermo Moyna

• A simple and remarkably accurate method for estimating the isotopic ratio between 10B and 11B through the use of 1H nuclear magnetic resonance (NMR) spectroscopy is presented. The experiment relies on the splitting caused by 10B (I = 3) and 11B (I = 3/2) on the 1H signal of a proton directly bound to boron, a phenomenon readily observed on an aqueous sample of NaBH4. In combination with a brief lecture or prelaboratory presentation, this laboratory can serve to introduce students to magnetic properties as well as theoretical and experimental aspects of NMR spectroscopy as early as the freshman-level chemistry.