Proton nuclear magnetic resonance, transition

Richardson, S.J. 1989. Contribution of proton exchange to the oxygen-17 nuclear magnetic resonance transverse relaxation rate in water and starch-water systems. Cereal Chem. 66, 244-246. Richardson, M.J. and Saville, N.G. 1975. Derivation of accurate glass transition temperatures by differential scanning calorimetry. Polymer 16, 753-757. 

The nuclear magnetic resonance (NMR) spectrum of chrom-3-ene (1) has been measured13 and the sign of coupling constants between protons on the hetero ring obtained from a study of double quantum transitions.13 An inter-ring coupling (J4 8) has been detected.14-16 In... 

Nuclear magnetic resonance (NMR) has been used to study segmental motions in block copolymer solutions. The mobility of protons in polymer chains in dilute solutions has been probed using high-resolution H NMR. Association of chains into micelles leads to a reduction in mobility in the core, which leads to a broadening of the respective NMR lines that has been studied for a number of systems, as described by Tuzar and Kratochvil (1993). The sol-gel transition in concentrated solutions has been located via ]H transverse relaxation time experiments, as outlined in Chapter 4. 

Nuclear magnetic resonance (NMR) spectroscopy (Section 14.1) A type of spectroscopy that uses transitions between the energy states of certain nuclei when they are in a magnetic field to supply information about the hydrocarbon part of a compound. There are two NMR techniques that are of most use to organic chemists proton magnetic resonance (lH-NMR) spectroscopy, which provides information about the hydrogens in a compound, and carbon-13 magnetic resonance spectroscopy (13C-NMR), which provides information about the carbons in a compound. 

Kalyanasundaram, K., Gratzel, M., and Thomas, J. K. (1975). J. Amer. Chem. Soc. 97, 3915. Electrolyte-Induced Phase Transitions in Micellar Systems. A Proton and Carbon-13 Nuclear Magnetic Resonances Relaxation and Photochemical Study. 

Nuclear magnetic resonance data on cyclohexane are reproduced together with heat capacity information in Fig. 3.2. The transition parameters are listed in Table 3.1. Below 150 K the experimental proton NMR second moment of 26.0 + 0.5 G corresponds to that calculated for a crystal of rigid molecules of Djj dymmetry in the chair conformation. The decrease in secoixi moment from 155 to 180 K is caused by jump-reorientation about the triad axis with a 46 kJ/mol activation energy. The experimental second moment somewhat below T of 6.4 G corresponds to the calculated value of 6.1 l.OG for such motion. At the transition the ond moment drops to 1.4 G which is in line with additional reorientation about aU other axes (1.3 to 1.1 G calculated for different assumptions). Above 240 K,... 

Fig. 8.—The Partial, H Nuclear Magnetic Resonance Spectrum of Sucrose Octaacetate (8) in Solution in Acetone-rid, With a Diagrammatic Representation of the First-order Assignment of the n-Glucose Protons is Shown in A. [The set of INDOR traces (B, C, D, and E) was obtained by sequentially monitoring transitions 1, 8, 5, and 3.]...

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