13C nuclear magnetic resonance of homologous methyl esters of saturated acids and the effect of chemical shift reagents

A homologous series of methyl esters was studied with13C Nuclear Magnetic Resonance (CMR) spectroscopy and compared to results which have been obtained with proton nuclear magnetic resonance (PMR) spectroscopy. Chemical shift reagents (CSRs) were used to improve the separation of resonances. The broader chemical shift range for CMR made possible the identification of each carbon as a unique resonance for methyl hexanoate through methyl nonanoate. The use of tris-(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octadione) Ytterbium (III) enables the separation of all carbons into unique resonances through methyl dodecanoate at 5KHz bandwidth. Carbon magnetic resonance is a useful tool for distinguishing members of homologous series and certainly more versatile than PMR.