THE ACIDITY OF SOME AROMATIC FLUORO ALCOHOLS AND KETONES

1960 ◽  
Vol 38 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Ross Stewart ◽  
R. Van der Linden
Keyword(s):  
Aqueous Solution ◽  
Nitro Compounds ◽  
Ionization Constants

A series of five trifluoroacetophenones and five phenyl trifluoromethyl carbinols have been synthesized and their ionization constants in water measured. They are the unsubstituted, p-methoxy, p-methyl, m-bromo, and m-nitro compounds. The ketones exist as hydrates in aqueous solution and each is about two pK units stronger than the corresponding alcohol. The acidities of both series are correlated by the Hammett relation with ρ values of 1.11 and 1.01 for the ketone hydrates and alcohols respectively. The acid strengths vary from a pKa of 9.18 for m-nitro-α,α,α-trifluoroacetophenone to 12.24 for p-methoxyphenyl trifluoromethyl carbinol.

Are all polar molecules hydrophilic? Hydration numbers of nitro compounds and nitriles in aqueous solution

2014 ◽  
Vol 16 (26) ◽  
pp. 13262-13270 ◽  
Author(s):  
Naoya Sagawa ◽  
Toshiyuki Shikata
Keyword(s):  
Aqueous Solution ◽  
Nitro Compounds ◽  
Polar Molecules ◽  
Hydration Numbers ◽  
Hydrophilic Hydration

Typical highly polar nitro compounds and nitriles should be classified ashydroneutralcompounds because of their hydration numbers of zero.

The Fine Structure of Cytosine

1962 ◽  
Vol 15 (4) ◽  
pp. 851 ◽  
Author(s):  
DJ Brown ◽  
M Lyall
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Fine Structure ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Spectrum ◽  
Tautomeric Form ◽  
Resonance Spectrum ◽  
Ionization Constants ◽  
Recent Formulation ◽  
Related Compounds

The ionization constants and ultraviolet spectra of cytosine, of its appropriately methylated derivatives, and of related compounds are used to indicate that its pre- dominant tautomeric form in aqueous solution is 4-amino-1,2-dihydro-2-oxopyrimidine. This is in sharp contrast to its recent formulation as a zwitterion on the grounds of its nuclear magnetic resonance spectrum.

Thermodynamic functions of ionization of t-butyl-substituted and methoxysubstituted phenols

1972 ◽  
Vol 25 (1) ◽  
pp. 75 ◽  
Author(s):  
PD Bolton ◽  
FM Hall ◽  
J Kudrynski
Keyword(s):  
Aqueous Solution ◽  
Thermodynamic Functions ◽  
Spectrophotometric Method ◽  
Substituent Effects ◽  
Steric Effects ◽  
Ionization Process ◽  
Ionization Constants ◽  
Temperature Range

Thermodynamic ionization constants of 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 3,5-di-t-butylphenol, and 3,5-dimethoxyphenol have been measured in aqueous solution by an e.m.f./spectrophotometric method within the temperature range 5-60�C and the thermodynamic functions of ionization ΔG25, ΔH25, ΔS25, and ΔCp25 calculated. These results confirm the additivity of substituent effects noted previously for the ionization of 3,5-disubstituted phenols and indicate that this ionization process is relatively insensitive to steric effects.

Sign in / Sign up

Export Citation Format

Share Document