Search results for "Oxygen-17"
showing 3 items of 3 documents
The hyperfine structure in the rotational spectra of D2(17)O and HD(17)O: Confirmation of the absolute nuclear magnetic shielding scale for oxygen
2015
Guided by theoretical predictions, the hyperfine structures of the rotational spectra of mono- and bideuterated-water containing (17)O have been experimentally investigated. To reach sub-Doppler resolution, required to resolve the hyperfine structure due to deuterium quadrupole coupling as well as to spin-rotation (SR) and dipolar spin-spin couplings, the Lamb-dip technique has been employed. The experimental investigation and in particular, the spectral analysis have been supported by high-level quantum-chemical computations employing coupled-cluster techniques and, for the first time, a complete experimental determination of the hyperfine parameters involved was possible. The experimental…
1H,13C,17O NMR and IR spectroscopic study of all methyl chloropropanoates
1994
1 H, 13 C and 17 O NMR chemical shifts, n J(H,H) and n J(C,H) spin-spin coupling constants and IR absorption maxima and intensities for the most characteristic bands of methyl propanoate and all eleven chloropropanoic acid methyl esters are reported
Substituted methyl 5β-cholan-24-oates. I—17O NMR spectral characterization
1994
Methyl esters of four common bile acids, 3α-hydroxy-5-β-cholan-24-oic (lithocholic) acid, 3α, 7α-dihydroxy-5β-cholan-24-oic (chenodeoxycholic) acid, 3α,12α-dihydroxy-5β-cholan-24-oic (deoxycholic) acid and 3α,7α,12α-trihydroxy-5β-cholan-24-oic (cholic) acid, and 14 acetylated, trifluoroacetylated, mesylated and oxo derivatives of methyl 5β-cholan-24-oates were prepared and their 17O NMR spectra recorded. In spite of their relatively high molecular masses and the rigid molecular structure of the steroid skeleton, most of the oxygens included in these structures gave well resolved 17O NMR resonance lines at natural abundance in 0.25–0.5 M acetonitrile solutions at 75°C. In agreement with the …