Nuclear magnetic resonance spectroscopy hydrogen bonds

Hydroboration-oxidation, 227-233, 250, 582 Hydroformylation, 661, 732 Hydrogen. See also Hydrogenation Nuclear magnetic resonance spectroscopy covalent bonding in, 12 formation of, 6 molecular orbitals, 34-35 nuclear spin states, 490-491 Hydrogenation. See also Heat of... 

Although Eibner elucidated the structure between 1904 and 1906, it was only through IR and nuclear magnetic resonance spectroscopy (NMR) that the chro-maticity of these molecules could be attributed to keto-enol tautomerism and simultaneous hydrogen bond formation (structures 137a = 137b) [2]. 

A reevaluation of molecular structure of humic substances based on data obtained primarily from nuclear magnetic resonance spectroscopy, X-ray absorption near-edge structure spectroscopy, electrospray ionization-mass spectrometry, and pyrolysis studies was presented by Sutton and Sposito (2005). The authors consider that humic substances are collections of diverse, relatively low molecular mass components forming dynamic associations stabilized by hydrophobic interactions and hydrogen bonds. These associations are capable of organizing into micellar structures in suitable aqueous environments. Humic components display contrasting molecular motional behavior and may be spatially segregated on a scale of nanometers. Within this new structural context, these components comprise any molecules... 

Cavitands. p. 219 Clathrate Hydrates, p. 274 Disorder and Diffuse Scattering, p. 457 Hydrogen Bonding, p. 658 Hydrophobic Effects, p. 673 Isostructurality of Inclusion Compounds, p. 767 Neutron Diffraction, p. 959 Soft and Smart Materials, p. 1302 Solid-State Nuclear Magnetic Resonance Spectroscopy, p. 1307... 

Stereochemical studies based on C-nuclear magnetic resonance spectroscopy ( C-NMR) showed the presence of eight cis and trans allylic hydroperoxides (Table 2.1). To determine the isomeric distribution of allylic hydroxyooctadecenoate derivatives, cis and trans fractions were separated by silver nitrate-thin layer chromatography (TLC), a procedure that separates according to the number, position and geometry of double bonds, and they were hydrogenated prior to GC-MS analyses of the TMS ether derivatives. More recently, the six major hydroperoxide isomers of methyl oleate were partially separated by silica HPLC, and identified by chemical-ionization mass spectrometry and IH NMR (Table 2.1). These hydroperoxide isomers were better separated as the hydroxy octadecenoate derivatives by the same silica HPLC method and re-analysed by GC-MS. 

L. Xie, H. Liu, S. Han, B. Yue, L. Yan, Hydrogen bond and proton transport in acid-base complexes and amphoteric molecules by density functional theory calculations and H and P nuclear magnetic resonance spectroscopy, J. Phys. Chem. B 117 (2013) 16345-16355. 

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