A Wide Line Nuclear Magnetic Resonance Study of Molecular Motion in n-Alkyl Ammonium Chlorides

1973 ◽  
Vol 51 (12) ◽  
pp. 1990-1994 ◽  
Author(s):  
J. Tsau ◽  
D. F. R. Gilson
Keyword(s):  
Fatty Acids ◽  
Molecular Motion ◽  
Nuclear Magnetic Resonance Study ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Magnetic Resonance Study ◽  
Line Nuclear Magnetic Resonance ◽  
Chain Axis ◽  
Wide Line ◽  
Alkyl Ammonium

Wide line n.m.r. studies of n-alkyl ammonium chlorides, C3–C10, show two transitions. The first transition is due to reorientation about the chain axis, the second to a transition to a mesomorphic phase. This phase is probably similar to that observed for the alkali metal salts of fatty acids.

A wide line nuclear magnetic resonance study of molecular motion in pyridinium salts

1970 ◽  
Vol 48 (16) ◽  
pp. 2625-2627 ◽  
Author(s):  
C. H. Matthews ◽  
D. F. R. Gilson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Molecular Motion ◽  
Nuclear Magnetic Resonance Study ◽  
Pyridinium Salts ◽  
Magnetic Resonance Study ◽  
Line Nuclear Magnetic Resonance ◽  
Pyridinium Ring ◽  
Wide Line ◽  
Nuclear Magnetic

Wide line nuclear magnetic resonance studies of pyridinium hexafluorophosphate, chloride, and nitrate show line width and second moment transitions which are attributed to reorientational motions of the pyridinium ring. The differences in transition temperatures are due to the different hydrogen bonded structures in the three salts.

A wide-line nuclear magnetic resonance study of molecular motions in piperidinium salts

1976 ◽  
Vol 54 (22) ◽  
pp. 3483-3486 ◽  
Author(s):  
Marie-Claude Bernard ◽  
Christopher Orvig ◽  
D. F. R. Gilson
Keyword(s):  
Crystal Structure ◽  
Nuclear Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Differential Scanning Calorimetric ◽  
Temperature Phase ◽  
Molecular Motions ◽  
Magnetic Resonance Study ◽  
Line Nuclear Magnetic Resonance ◽  
Wide Line ◽  
Calorimetric Studies

Wide line nmr and differential scanning calorimetric studies confirm the existence of crystal phase transitions in piperidinium iodide. The highest temperature phase involves isotropic rotation of the piperidinium ion. No crystal structure transitions occur in the chloride, bromide, or hexafluorophosphate salts although these compounds undergo second moment transitions indicating probable rotation of the piperidinium ion about the N—C3 axis.

Polymorphism in n-Alkylammonium Halides. A Wide Line Nuclear Magnetic Resonance Study of the Chlorides C11—C15

1974 ◽  
Vol 52 (13) ◽  
pp. 2421-2424 ◽  
Author(s):  
J. Tsau ◽  
D. F. R. Gilson
Keyword(s):  
Crystal Structure ◽  
Nuclear Magnetic Resonance Study ◽  
Temperature Transition ◽  
Magnetic Resonance Study ◽  
Scanning Calorimetry ◽  
Line Nuclear Magnetic Resonance ◽  
Wide Line ◽  
Higher Temperature ◽  
Chain Compounds ◽  
Alkylammonium Halides

Wide line n.m.r. studies of the n-alkylammonium chlorides C12—C15 show a nonreversible behavior which parallels that observed using differential scanning calorimetry. For samples which have been heated above the nonreversible transition the temperature dependence of the line width and second moment resemble that of the shorter chain compounds of this series; one transition due to the onset of chain rotation and a second higher temperature transition due to more extended motion probably of a translational nature. A change in crystal structure is proposed in order to explain the nonreversibility.

MOLECULAR MOTION IN WEAK CHARGE TRANSFER COMPLEXES

1966 ◽  
Vol 44 (8) ◽  
pp. 945-952 ◽  
Author(s):  
D. F. R. Gilson ◽  
C. A. McDowell
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Charge Transfer ◽  
Molecular Motion ◽  
Charge Transfer Complexes ◽  
Weak Charge ◽  
Magnetic Resonance Studies ◽  
Second Moments ◽  
Line Nuclear Magnetic Resonance ◽  
Pure Compounds ◽  
Wide Line

"Wide line" nuclear magnetic resonance studies of several charge transfer complexes are reported. Line width transitions and comparisons of theoretical and experimental second moments indicate that molecular rotation occurs in several of these complexes. Estimates of the barriers to reorientation in the complexes show these to be lower than those observed for the corresponding pure compounds.

Sign in / Sign up

Export Citation Format

Share Document