Intermolecular and Hydrogen Bonding Effects

Two different charge models were applied to take into account intermolecular interactions to model the solid-state effects on the F NMR chemical shift tensors. The interpretation of H NMR chemical shifts, coupling constants, and coefficients of temperature dependence (6(OH), /(H,OH), and A8(OH)/AT values) evidences that, in DMSO solution, the signal of an OH 

The molecular structures and intramolecular hydrogen bonding for salicylic (I), 2-hydroxythiobenzoic (II), 2-hydroxythionobenzoic (III) and 2-hydroxy-dithiobenzoic acids (IV) were studied precisely by ab initio method and density functional theory. The carbonyl electrical field-gradient (EFG) tensor and chemical shift (CS) tensor of a urea-type functional group, R NH-C(0)-NHR were determined. Quantum chemical calculations revealed very large 

A number of disaccharides with 1,3-, 1,4- and 1,6-linkages have been investigated in a continuing study on the use of hydroxy protons in conformational analysis of saccharides in aqueous solution by NMR. The intramolecular N-H-- 0 hydrogen bonds formed by a number of heteroconjugated systems (P-enaminones, ketohydrazones, and nitrosoenamines) were studied by X-ray, IR and NMR spectroscopic, and quantum-mechanical calculation.  

A review with 49 references was given. Hydrogen bond lengths on enzymes have been derived with high precision ( 0.05 A) from both the proton chemical shifts (8) and the fractionation factors (q ) of the proton involved and were compared with those obtained from protein X-ray crystallography, 

A series of amide oligomers have been prepared from isophthalic acid and bisaniline derivatives. These compounds assemble into double-stranded zipper complexes in solution via hydrogen-bonding and edge-to-face aromatic interactions. The stabihty and structures of the complexes were determined by H NMR in chloroform solution. 

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