An analysis of 13C nuclear magnetic resonance substituent chemical shifts in 3-substituted thiophene-2-carboxylic and 2-substituted benzoic acids by linear free energy relationships

1988 ◽  
pp. 887 ◽  
Author(s):  
Renato Noto ◽  
Liliana Lamartina ◽  
Caterina Arnone ◽  
Domenico Spinelli
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Free Energy ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Benzoic Acids ◽  
Linear Free Energy Relationships ◽  
Linear Free Energy ◽  
13C Nuclear Magnetic Resonance ◽  
Energy Relationships ◽  
Substituted Benzoic Acids

Substituent effects on the N.M.R. spectra of carboxylic acid derivatives. III. Correlation of 13C N.M.R. spectra of para substituted acetanilides and 4'-nitrophenyl 4-substituted benzoates with infrared carbonyl stretching frequencies, 1H N.M.R., rate and equilibrium data

1984 ◽  
Vol 37 (3) ◽  
pp. 497 ◽  
Author(s):  
CJ O'Conner ◽  
DJ McLennan ◽  
DJ Calvert ◽  
TD Lomax ◽  
AJ Porter ◽  
...  
Keyword(s):  
Free Energy ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Linear Free Energy Relationships ◽  
Reactive Site ◽  
Linear Free Energy ◽  
Equilibrium Data ◽  
Energy Relationships ◽  
Monosubstituted Benzenes ◽  
Best Fit

The 13C n.m.r. spectra of 17 monosubstituted benzenes, 14 para substituted acetanilides and ten 4'-nitrophenyl 4-substituted benzoates have been measured in (CD3)2SO and the chemical shifts have been compared with the infrared carbonyl stretching frequencies of the substrates (in CCl4), the 1H n.m.r. chemical shifts of protons close to the reactive site of protonation, rates of hydrolysis or aminolysis and literature values of the corresponding basicity constants and rate constants. The observed substituent chemical shifts are non-additive and this result has been discussed in terms of the electronic properties of -NHCOCH3 and -COOC6H4NO2. The 13C n.m.r. and the i.r. data have been treated by single parameter and dual substituent parameter linear free energy relationships and σR values of best fit have been identified. Relative resonance and inductive contributions have been discussed.

Linear Free-Energy Relationships Applied to the13C NMR Chemical Shifts in 4-SubstitutedN-[1-(Pyridine-3- and -4-yl)ethylidene]anilines

2014 ◽  
Vol 51 (5) ◽  
pp. 1442-1451 ◽  
Author(s):  
Milica Rančić ◽  
Nemanja Trišović ◽  
Miloš Milčić ◽  
Maja Jovanović ◽  
Bratislav Jovanović ◽  
...  
Keyword(s):  
Free Energy ◽  
Chemical Shifts ◽  
Linear Free Energy Relationships ◽  
Nmr Chemical Shifts ◽  
Linear Free Energy ◽  
Energy Relationships
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