Proton donor ability of surface hydroxy groups from the IR spectra of hydrogen-bonded complexes

1978 ◽  
Vol 9 (3) ◽  
pp. 265-268 ◽  
Author(s):  
E. A. Paukshtis ◽  
L. G. Karakchiev ◽  
N. S. Kotsarenko
Keyword(s):  
Ir Spectra ◽  
Proton Donor ◽  
Donor Ability ◽  
Hydroxy Groups ◽  
Bonded Complexes ◽  
Hydrogen Bonded

scholarly journals Vibrational spectroscopic studies of hydrogen‒bonded complexes between 2,5-dihydroxy-P-benzoquinone and amines

2001 ◽  
Vol 15 (1) ◽  
pp. 33-44 ◽  
Author(s):  
MoustafaM. Habeeb ◽  
Hoda A. Al-Wakil ◽  
Aly El-Dissouky ◽  
Nesrine M. Refat
Keyword(s):  
Ir Spectra ◽  
Critical Behavior ◽  
Spectroscopic Studies ◽  
Base Line ◽  
Ir Absorption ◽  
Deep Minimum ◽  
Nitrogen Bases ◽  
Ft Ir ◽  
Bonded Complexes ◽  
Hydrogen Bonded

A series of 1 :1 hydrogen-bonded complexes between 2,5-dihydroxy-P-benzoquinone (DHBQ) and various nitrogen bases of different strengths were prepared. The FT-IR spectra of the prepared complexes were examined in different regions. It has been found that the protonic and carbonyl vibrations are strongly affected by protonation. The intensity of protonic vibrations was estimated, the base line was corrected by using Perkin-Elmer Paragon 1000 program. A maximum was found at pKa= 5.6 in the correlation between the intensity and pKa(amines) suggesting a critical behavior. The same value was located as a deep minimum in the correlation between the center of gravity of the protonic vibrations, vcgcm−1, and the pKaof the amines confirming the critical behavior in some of the studied complexes. The effect of the contribution of the second OH group to the IR absorption profile was discussed. Finally, the FT-IR spectra of some deuterated complexes were presented and analysed.

scholarly journals Dielectric Relaxation Studies of Hydrogen Bonded Complexes of Benzamide and Acetamide with 4-substituted Phenols Using X-band Microwave Frequency

2021 ◽  
Vol 38 (3) ◽  
Author(s):  
A. Aathif Basha ◽  
F. Liakath Ali Khan
Keyword(s):  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Proton Donor ◽  
Single Frequency ◽  
Hydroxyl Group ◽  
Molar Ratio ◽  
Frequency Method ◽  
Dielectric Parameters ◽  
Bonded Complexes ◽  
Hydrogen Bonded

At 308 K, using a 9.37 GHz dielectric relaxation setup, dielectric studies of hydrogen bonded complexes of benzamide and acetamide with 4-fluorophenol, 4-bromophenol, 4-chlorophenol, and 4-iodophenol in benzene were performed. Various dielectric parameters (such as ??, ??, ?0, and ??) were tested. The steric interactions of the proton donor determined the group rotation relaxation time t(2), whereas the significance of Higasi’s single frequency method for multiple relaxation time t(1) was determined by the hydrogen bonding power of the phenolic hydrogen. The presence of a 1:1 complex system between the prepared samples, as well as a charge transfer between the free hydroxyl group of phenols and the carbonyl group of amides was confirmed by the fact that the relaxation time and molar free energy activation of the 1:1 molar ratio were greater than some other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3).

Estimation of proton donor ability of surface hydroxy groups in terms of proton affinity

1981 ◽  
Vol 16 (2-3) ◽  
pp. 131-135 ◽  
Author(s):  
E. A. Paukshtis ◽  
E. N. Yurchenko
Keyword(s):  
Proton Affinity ◽  
Proton Donor ◽  
Donor Ability ◽  
Hydroxy Groups
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