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13C NMR Spectroscopy for the Quantitative Determination of Compound Ratios and Polymer End Groups
- Otte, Douglas
A. L., Borchmann, Dorothee E., Lin, Chin, Weck, Marcus, Woerpel, K. A.
- Organic letters 2014 v.16 no.6 pp. 1566-1569
- carbon, chemical reactions, diastereomers, gas chromatography, high performance liquid chromatography, molecular weight, nuclear magnetic resonance spectroscopy, polymers, positional isomers, quantitative analysis, stable isotopes, sugars
- ¹³C NMR spectroscopic integration employing short relaxation delays was evaluated as a quantitative tool to obtain ratios of diastereomers, regioisomers, constitutional isomers, mixtures of unrelated compounds, peptoids, and sugars. The results were compared to established quantitative methods such as ¹H NMR spectroscopic integration, gas chromatography, and high-performance liquid chromatography and were found to be within <3.4% of ¹H NMR spectroscopic values (most examples give results within <2%). Acquisition of the spectra took 2–30 min on as little as 10 mg of sample, proving the general utility of the technique. The simple protocol was extended to include end group analysis of low molecular weight polymers, which afforded results in accordance with ¹H NMR spectroscopy and matrix-assisted laser desorption-ionization time-of-flight spectrometry.