A Carbon-13 Nuclear Magnetic Resonance Study of Cation Solvation in Alcohols

1974 ◽  
Vol 52 (5) ◽  
pp. 744-748 ◽  
Author(s):  
Gerald W. Stockton ◽  
John S. Martin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Exchange Rates ◽  
Low Temperatures ◽  
Solvation Shell ◽  
Nuclear Magnetic Resonance Study ◽  
Solvent Exchange ◽  
Magnetic Resonance Study ◽  
Sign Reversal ◽  
Solvation Complex

Natural abundance 13C spectra of solvent coordinated to the cation have been observed in solutions of Mg(II) and Al(III) salts in alcohols. Carbon shielding changes induced by cations resemble those induced by electronegative substituents; a sign reversal between the β and γ positions is found in both instances. Solvent exchange rates correspond to those found by 1H n.m.r.; this confirms that whole molecule exchange is dominant. Selective relaxation of the solvation shell signals at low temperatures reflects differences in conformational mobility within the solvation complex.

A nuclear magnetic resonance study of exchange reactions in the system boron trifluoride – methanol. A modified interpretation

1967 ◽  
Vol 45 (19) ◽  
pp. 2243-2246 ◽  
Author(s):  
R. J. Gillespie ◽  
J. S. Hartman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Low Temperatures ◽  
Boron Trifluoride ◽  
Proton Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Methyl Groups ◽  
Exchange Reactions ◽  
Magnetic Resonance Study ◽  
Methanol Solutions

The proton magnetic resonance spectra of boron trifluoride – methanol solutions in sulfur dioxide, with methanol in excess, are interpreted in terms of equilibria between methanol, methanol·BF3, and (methanol)2·BF3. The two methyl peaks observed in the spectra at low temperatures may be attributed to methyl groups in free and complexed methanol (i.e. methanol in which the oxygen is coordinated by BF3).

A 19F Nuclear Magnetic Resonance Study of Halogen Exchange between Antimony Pentafluoride and Inorganic Chlorides. Complexes of Antimony and Arsenic Pentafluorides with Carbonyl Fluoride

1971 ◽  
Vol 49 (8) ◽  
pp. 1276-1283 ◽  
Author(s):  
J. Bacon ◽  
P. A. W. Dean ◽  
R. J. Gillespie
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Low Temperatures ◽  
Nuclear Magnetic Resonance Study ◽  
Antimony Pentafluoride ◽  
Magnetic Resonance Study ◽  
Halogen Exchange ◽  
Donor Acceptor ◽  
Carbonyl Fluoride ◽  
Nuclear Magnetic

19F nuclear magnetic resonance (n.m.r.) has been used to study the reactions occurring in the systems SbCl5–SbF5–SO2ClF, SO2Cl2–SbF5–SO2ClF, COF2–SbF5–SO2ClF, COF2–AsF5–SO2ClF, and COClF–SbF5–SO2ClF. Ionization occurs in SbCl5–SbF5–SO2ClF, yielding antimony chloro- and chloro-fluorocations and antimony polyfluoroanions. Donor-acceptor complexes are formed between SbF5 and SO2Cl2, COF2 or COClF at low temperatures and also between AsF5 and COF2. In all the complexes the ligand is oxygen-bonded. At higher temperatures halogen exchange and ionization occurs in SO2Cl2–SbF5–SO2ClF and COClF–SbF5–SO2ClF giving SO2ClF and COF2 complexes, respectively, together with antimony cations and polyfluoroanions. The alkyl chloride –SbF5 reaction is also shown to give chlorine-containing cations of antimony.

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