Solvent Effects on the Spin-Lattice Relaxation Times and Chemical Shifts ofN-Methylacetamide andN,N-Dimethylacetamide in Hydrogen Bonding Solvents
نویسندگان
چکیده
منابع مشابه
Isotope Effects on Deuterium Spin-Lattice Relaxation
The deuterium spin-lattice relaxation time, 7",, of H 2 0 /D 2 0 mixtures is measured at 298.2 K. The relaxation rate, Ff 1 , is found to increase with increasing deuterium atom fraction, n, the plot of T\ 1 vs. n exhibiting a small depature from linearity. A general equation Tf 1 (n) for the H 2 0 / DiO system is formulated. The temperature dependence of Tx is investigated in the temperature r...
متن کاملEffects of protonation and hydrogen bonding on carbon-13 chemical shifts of compounds
MALWINA LLEN and JOHN D. ROBERTS. Can. J. Chem. 59,451 (1981). The effects of hydrogen bonding and protonation produced by changing solvent from chloroform to 2,2,2-trifluoroethanol to trifluoroacetic acid were determined for the 13C chemical shifts of fourteen imines, four oximes, and two pyridines. Downfield shifts relative to chloroform were observed for the C=N carbon of the imines and oxim...
متن کاملStructural Applications of Nuclear Spin-lattice Relaxation Times
The structural utility of three mechanisms of nuclear spin relaxation are considered. Examples illustrating the applicability of nuclear-nuclear dipolar relaxation in determining molecular microdynamics and solution geometry are presented. The use of spin-rotation relaxation to determine barriers to CH3 groups rotations and an example of quadrupole relaxation of deuteriums to probe molecular mo...
متن کاملStandardization of chemical shifts of TMS and solvent signals in NMR solvents.
The standard for chemical shift is dilute tetramethylsilane (TMS) in CDCl3, but many measurements are made relative to TMS in other solvents, the proton resonance of the solvent peak or relative to the lock frequency. Here, the chemical shifts of TMS and the proton and deuterium chemical shifts of the solvent signals of several solvents are measured over a wide temperature range. This allows fo...
متن کاملHydrogen bonding vs. halogen bonding: the solvent decides.
Control of intermolecular interactions is integral to harnessing self-assembly in nature. Here we demonstrate that control of the competition between hydrogen bonds and halogen bonds, the two most highly studied directional intermolecular interactions, can be exerted by choice of solvent (polarity) to direct the self-assembly of co-crystals. Competitive co-crystal formation has been investigate...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin of the Chemical Society of Japan
سال: 1971
ISSN: 0009-2673,1348-0634
DOI: 10.1246/bcsj.44.2931