Réactions dans le sulfolane. VI. Etude de solutions des acides perchlonque, fluorosulfurique, pyrosulfurique et hexachloroantimonique

1970 ◽  
Vol 48 (15) ◽  
pp. 2353-2359 ◽  
Author(s):  
R. L. Benoit ◽  
C. Buisson ◽  
G. Choux
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aprotic Solvent ◽  
Strong Acid ◽  
Acid Strength ◽  
Protic Solvent ◽  
Dilute Solution ◽  
Conductivity Data ◽  
Dipolar Aprotic Solvent ◽  
Nuclear Magnetic

Nuclear magnetic resonance and certain conductivity data are reported for solutions of perchloric and fluorosulfuric acids in sulfolane. Additional measurements were made on solutions of disulfuric and hexachloroantimony (V) acids. HSbCl6 is a strong acid in this weakly basic dipolar aprotic solvent. HClO4, HSO3F, and H2S2O7 are incompletely dissociated with K = 10−2.7, 10−3.3, and ~ 10−5, respectively. The acid strength in dilute solution in sulfolane follows the order HClO4 > HSO3F > H2S2O7, which differs from that known in H2SO4 which is a strongly associated polar protic solvent.

The conformational behavior of isobutylbenzene in CS2/C6D12 solution at 300 K

1992 ◽  
Vol 70 (9) ◽  
pp. 2370-2374 ◽  
Author(s):  
Ted Schaefer ◽  
Lina B.-L. Lee
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Spectrum ◽  
Resonance Spectrum ◽  
Statistical Weight ◽  
Conformational Behavior ◽  
Dilute Solution ◽  
Gauche Conformer ◽  
Internal Barriers ◽  
Nuclear Magnetic

The 1H nuclear magnetic resonance spectrum of isobutylbenzene as a dilute solution in CS2/C6D12 at 300 K is analyzed. The gauche conformer (statistical weight 2) predominates, as was previously shown for a jet-cooled stream of this compound. The apparent twofold barrier to rotation about the Csp2—Csp3 bond is 10.5 ± 0.5 kJ/mol, as must be the case for the analogous gauche conformer of n-propylbenzene. The internal barriers are compared for ethylbenzene, gauche isobutylbenzene, and neopentylbenzene. AM1 and STO-3G MO computations of the conformer stabilities and barriers are reported, the latter being in better agreement with experiment.

FAST REARRANGEMENT OF exo-NORBORNANOL IN STRONG ACID SOLUTIONS

1965 ◽  
Vol 43 (3) ◽  
pp. 674-678 ◽  
Author(s):  
Gideon Fraenkel ◽  
Phillip D. Ralph ◽  
John P. Kim
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Strong Acid ◽  
Acid Solutions ◽  
Nuclear Magnetic Resonance Spectra ◽  
Strong Acids ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectra have been obtained at several temperatures for solutions of 2-exo-norbornanol in strong acids. The spectra change with temperature reversibly. It is concluded that the 2-exo-norbornanol undergoes very rapid rearrangement, the fast steps being 2,6 and 3,2 hydride shifts, respectively.

CHEMISTRY OF ETHYL 2-METHYL-4-OXO-Δ2-PYRROLINE-3-CARBOXYLATE AND RELATED COMPOUNDS

1964 ◽  
Vol 42 (7) ◽  
pp. 1524-1529 ◽  
Author(s):  
R. S. Atkinson ◽  
E. Bullock
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Strong Acid ◽  
Alternative Route ◽  
Methyl Derivative ◽  
Oxidizing Agents ◽  
Related Compounds ◽  
Nuclear Magnetic

Ethyl 2-methyl-4-oxo-Δ2-pyrroline-3-carboxylate (Ia) is oxidized by one-electron oxidizing agents to a colored dimer which has been synthesized by an alternative route. Acetylation of (Ia) and its N-methyl derivative (Ib) gives a variety of products some of which show unusual infrared absorptions. The products of dimerization of (Ia) and (Ib) in strong acid show nuclear magnetic resonance absorptions at variance with previously claimed structures and alternatives are suggested.

Aprotic solvent effects on the fluorine nuclear magnetic resonance shifts of p-substituted fluorobenzenes

1972 ◽  
Vol 94 (20) ◽  
pp. 7208-7209 ◽  
Author(s):  
R. T. C. Brownlee ◽  
S. K. Dayal ◽  
J. L. Lyle ◽  
R. W. Taft
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Solvent Effects ◽  
Aprotic Solvent ◽  
Nuclear Magnetic
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