Complex fluoroanions in solution. XI. Complexes of silicon, germanium, and titanium tetrafluorides with simple anions

1980 ◽  
Vol 58 (14) ◽  
pp. 1407-1411 ◽  
Author(s):  
S. Brownstein

A fluorine-bridged silicon fluoroanion and many hexa-co-ordinate germanium and titanium fluoroanions have been identified in solution via fluorine magnetic resonance. A generalized shceme is used to correlate all fluorine chemical shift data for hexa-coordinate fluorine containing species.

1964 ◽  
Vol 17 (6) ◽  
pp. 632 ◽  
Author(s):  
JW Clark-Lewis ◽  
LM Jackman ◽  
TM Spotswood

Chemical-shift and coupling-constant data for protons in 68 flavan derivatives are reported. Coupling-constant data for interactions involving the 2-, 3-, and 4-protons have been used to define the configuration of the 2-, 3-, and 4-substituents and the conformation of the heterocyclic ring. It is shown that chemical-shift data for protons of the heterocyclic ring and of 3- and 4-acetoxyl groups are of little value in stereochemical studies. Analysis of the absorptions of the aromatic protons shows that N.M.R. is useful for determining the oxygenation pattern in rings A and B.


1970 ◽  
Vol 48 (12) ◽  
pp. 1919-1923 ◽  
Author(s):  
Donald G. Lee

The [Formula: see text] values for 3-pentanone, 2-butanone, and 3-methyl-2-butanone have been determined from chemical shift data. The values (−7.6, −7.1, and −7.2, respectively) are in good agreement with those previously determined for aliphatic ketones by use of ultraviolet–visible and Raman spectroscopy.


1987 ◽  
Vol 65 (6) ◽  
pp. 1214-1217 ◽  
Author(s):  
David W. Boykin ◽  
Alfons L. Baumstark ◽  
Margaret M. Kayser ◽  
Chantal M. Soucy

17O chemical shift data (natural abundance) for 3-substituted phthalic anhydrides and 4- and 7-substituted phthalides in acetonitrile at 75 °C are reported. Steric interactions of substituents ortho to the carbonyl groups result in deshielding effects (9–22 ppm) relative to parent compounds regardless of the electronic character of the substituents. Factors contributing to the deshielding effects are discussed. The relationship between 17O chemical shifts and regiochemistry of the phthalic anhydrides is discussed.


1993 ◽  
Vol 47 (4) ◽  
pp. 411-422 ◽  
Author(s):  
R. A. Nyquist

Infrared (IR) and/or Nuclear Magnetic Resonance (NMR) carbon-13 data are presented for 3- x and 4- x substituted anilines. Correlations are presented for the δ13C-1 chemical shift vs. Hammett δ p and δ m values, vasym., NH2 vs. δ13C-1, vsym. NH2 vs. δ13C-1, δ13C-1 vs. vasym. NH2, δ13C-1 vs. the absorbance ratio A( vasym. NH2/ A( vsym. NH2), and δ13C-l vs. Taft δ R°. The IR data for these compounds are recorded in the vapor phase, and in hexane, carbon tetrachloride, and chloroform solutions. The NMR chemical shift data for these compounds in solution with chloroform were obtained with the use of tetramethylsilane as the δ13C resonance reference frequency.


1975 ◽  
Vol 53 (6) ◽  
pp. 836-844 ◽  
Author(s):  
N. Plavac ◽  
I. W. J. Still ◽  
M. S. Chauhan ◽  
D. M. McKinnon

Carbon-13 chemical shift data have been obtained for a number of isothiazole, benzo[c]isothiazole, 1,2-dithiole, and 1,3-dithiole derivatives. A number of these compounds are thiones and the chemical shifts of the C=S carbons are discussed in the light of recent attempts to predict such chemical shifts from those of the analogous carbonyl compounds. Comparisons of substituent chemical shift (s.c.s.) effects in these heterocyclic compounds with those in simpler aromatic or conjugated systems have been made and additivity correlations tested in a number of cases.


1976 ◽  
Vol 29 (8) ◽  
pp. 1671 ◽  
Author(s):  
AJ Birch ◽  
PW Westerman ◽  
AJ Pearson

The carbon-13 N.M.R. spectra of eleven substituted tricarbonylcyclohexadienyliron salts (1) have been determined and individual resonances assigned. Substituent effects have been deduced and compared with corresponding effects in cyclohexadienyl cations. The structures of the tricarbonylcyclohexadienyliron salts are discussed with reference to chemical shift data. The proportions of irreversible nucleophilic attack at the terminal positions in the unsymmetrical 2-substituted salts are compared with the observed chemical shifts at these carbon atoms.


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