Medium effects in nuclear magnetic resonance. VII. Vapor phase studies of hydrogen bonding in methanol and methanol–trimethylamine mixtures

1969 ◽  
Vol 47 (4) ◽  
pp. 625-629 ◽  
Author(s):  
A. D. H. Clague ◽  
G. Govil ◽  
H. J. Bernstein
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Vapor Phase ◽  
The Self ◽  
Resonance Spectroscopy ◽  
Kcal Mole ◽  
Medium Effects ◽  
Intermolecular Association ◽  
Self Association ◽  
Nuclear Magnetic

The self association of methanol, and the intermolecular association of methanol and trimethylamine have been examined in the vapor phase using nuclear magnetic resonance spectroscopy. Values of ΔH and ΔS for the two systems have been found to be −4.1 ± 0.5 kcal/mole and −17.5 ± 3 e.u., and −5.8 ± 0.7 kcal/mole and −22.6 ± 3 e.u., respectively.

scholarly journals A Fast Self-Learning Subspace Reconstruction Method for Non-Uniformly Sampled Nuclear Magnetic Resonance Spectroscopy

2020 ◽  
Vol 10 (11) ◽  
pp. 3939 ◽  
Author(s):  
Zhangren Tu ◽  
Huiting Liu ◽  
Jiaying Zhan ◽  
Di Guo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
The Self ◽  
Resonance Spectroscopy ◽  
Reconstruction Method ◽  
Subspace Method ◽  
High Quality ◽  
Self Learning ◽  
Nuclear Magnetic

Multidimensional nuclear magnetic resonance (NMR) spectroscopy is one of the most crucial detection tools for molecular structure analysis and has been widely used in biomedicine and chemistry. However, the development of NMR spectroscopy is hampered by long data collection time. Non-uniform sampling empowers rapid signal acquisition by collecting a small subset of data. Since the sampling rate is lower than that of the Nyquist sampling ratio, undersampling artifacts arise in reconstructed spectra. To obtain a high-quality spectrum, it is necessary to apply reasonable prior constraints in spectrum reconstruction models. The self-learning subspace method has been shown to possess superior advantages than that of the state-of-the-art low-rank Hankel matrix method when adopting high acceleration in data sampling. However, the self-learning subspace method is time-consuming due to the singular value decomposition in iterations. In this paper, we propose a fast self-learning subspace method to enable fast and high-quality reconstructions. Aided by parallel computing, the experiment results show that the proposed method can reconstruct high-fidelity spectra but spend less than 10% of the time required by the non-parallel self-learning subspace method.

Nuclear magnetic resonance studies. X. Determination of the thermodynamic parameters of the self-association of tricyclic aromatic aldehydes in solution

1967 ◽  
Vol 45 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Gurudata ◽  
R. E. Klinck ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Temperature Dependence ◽  
Thermodynamic Parameters ◽  
Aromatic Aldehydes ◽  
The Self ◽  
Kcal Mole ◽  
Magnetic Resonance Studies ◽  
Self Association

The temperature dependence of the formyl proton shieldings of 9-anthraldehyde and 9-phenanthraldehyde in chloroform solutions has been measured. Four concentrations in the range 0.5–5.0 mole % were examined over the temperature interval − 60 to + 90 °C. From these results, the enthalpies and entropies of formation have been estimated for the complex formed by the self-association of two aldehyde molecules. The calculations indicate the ΔH and ΔS values to be − 1.9 ± 0.3 kcal/mole and − 6 ± 1 e.u., respectively. These results are compared with other available data.

NMR Study of Hydrogen Bonding Association of some Sterically Hindered Alcohols in Carbon Tetrachloride, Chloroform and Cyclohexane

2002 ◽  
Vol 216 (7) ◽  
Author(s):  
W.-C. Luo ◽  
J.-L. Lay ◽  
Jenn-Shing Chen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
The Self ◽  
Resonance Spectroscopy ◽  
Nmr Study ◽  
Self Association

The self-association (dimerization) due to hydrogen bonding for some alcohols with bulky side chains was investigated by nuclear magnetic resonance spectroscopy. The systems studied include 2,4-dimethyl-3-pentanol or 3-methyl-3-pentanol in [

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