Cis-trans isomerizations of 1-lithio-1-phenyl-1-butene. Solvent effects on the rate of isomerization and on nuclear magnetic resonance spectra

1975 ◽  
Vol 97 (14) ◽  
pp. 3996-4000 ◽  
Author(s):  
Edward J. Panek ◽  
Bruce L. Neff ◽  
Houng Chu ◽  
Mary G. Panek
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Solvent Effects ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

SOLVENT EFFECTS IN THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF BENZALMALONONITRILES

1965 ◽  
Vol 43 (9) ◽  
pp. 2585-2593 ◽  
Author(s):  
M. A. Weinberger ◽  
R. M. Heggie ◽  
H. L. Holmes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Solvent Effects ◽  
Benzene Solution ◽  
Chemical Shifts ◽  
Olefinic Proton ◽  
Solvent Molecule ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra of a series of substituted benzalmalononitriles were examined in various solvents. The chemical shifts for the olefinic protons are susceptible to large solvent effects which are interpreted as arising from association of a solvent molecule with the olefinic proton (acetone) or a site in its vicinity (benzene). With acetone this leads to a downfield shift from values observed in chloroform. In benzene solution the association produces increased shielding and is present in addition to a second solvation complex, the arrangement of which is governed by the substituent. The difference in behavior of the ethylenic proton in benzalmalononitriles from the formyl proton in benzaldehyde is ascribed to its more highly acidic nature.

Solvent Effects in Nuclear Magnetic Resonance Spectra

1960 ◽  
Vol 32 (4) ◽  
pp. 1227-1233 ◽  
Author(s):  
A. D. Buckingham ◽  
T. Schaefer ◽  
W. G. Schneider
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Solvent Effects ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Solvent Effects in the Nuclear Magnetic Resonance Spectra of Benzal Compounds

1974 ◽  
Vol 28 (2) ◽  
pp. 146-151 ◽  
Author(s):  
M. A. Weinberger ◽  
F. H. Meppelder ◽  
G. G. Nicholson ◽  
H. L. Holmes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Solvent Effect ◽  
Solvent Effects ◽  
Side Chain ◽  
Nuclear Magnetic Resonance Spectra ◽  
Solvent Shifts ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectra of benzal compounds, Z—C6H4—CH=C(X)Y, have been determined in carbon tetrachloride, chloroform, acetone, and benzene solutions. Group X, trans to the ring, was one of NO2, COOEt, COCH3, CONH2, the series comprising mostly para-substituted (Z=NO2, Cl, H, Me, OMe, NMe2) β-nitrostyrenes, β-alkyl-β-nitrostyrenes, cinnamates, cyanocinnamates, malonates, acetoacetates, acetylacetones, and cyanocinnamides. The ambiguity in the assignments to the olefinic protons in the β-nitrostyrenes was resolved by studying deuterated compounds. The solvent shifts for the aromatic protons are shown to be additive, the olefinic side chains and the ring substituents making characteristic contributions. The solvent effect for the aromatic protons ortho to the side chain is most affected by variation of the latter and, when large, may contribute to the effect at the olefinic protons. The β-nitrostyrenes show the largest solvent shifts for the olefinic protons, and the reasons for the more marked effects at the β-proton are discussed.

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