17O-NMR Evidence on the Isolated Water Molecule in Hydrophobic Organic Solvents

Abstract 17O-NMR spectra of H217O molecules in benzene, chloroform, ethylacetate, dimethylformamide, and 1-butanol were measured. For hydrophobic benzene and chloroform, the 17O-NMR spectra give two peaks consisting of the triplet and singlet lines, which are assingned to the isolated monomeric and clustered water molecules, respectively. The observed triplet splitting due to the spin - spin coupling of J17O-H gives an evidence that the isolated water molecule can not exchange the protons between water molecules seperated far away during the measurement time of NMR phenomenon.