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).

scholarly journals Microwave Dielectric Study of Tetramethylurea andN, N-Dimethylacetamide Binary Mixture in Benzene

2011 ◽  
Vol 8 (3) ◽  
pp. 1378-1386
Author(s):  
V. Sharma ◽  
N. Thakur
Keyword(s):  
Dielectric Constant ◽  
Binary Mixture ◽  
Dielectric Relaxation ◽  
Benzene Solution ◽  
Microwave Frequency ◽  
Single Frequency ◽  
Rate Theory ◽  
Dielectric Study ◽  
Frequency Method ◽  
Dielectric Parameters

Dielectric relaxation of the binary mixture of tetramethylurea andN, N-dimethylacetamide has been studied at fixed frequency and temperature (9.88 GHz & 298 K respectively) in benzene solution. Different dielectric parameters like the dielectric constant (ε') and the dielectric loss (ε") at microwave frequency, static dielectric constant (ε0) and dielectric constant (ε∞) at optical frequency were determined. The values of relaxation time (τ(1), τ(2), τ(0)& τGK) have been calculated using higasi’s single frequency method and Gopala Krishna’s method. Using Eyring’s rate theory, the activation energies for the process of dielectric relaxation and viscous flow were calculated and compared. The study of dielectric properties of the binary mixture reveals the existence of the solute-solute type of molecular associations.

MOLECULAR INTERACTION STUDY OF N-BENZYLFORMAMIDE WITH 1-ALCOHOLS USING X-BAND MICROWAVE

2010 ◽  
Vol 24 (02) ◽  
pp. 195-200
Author(s):  
M. S. MANJUNATH ◽  
J. SANNAPPA
Keyword(s):  
Relaxation Time ◽  
Binary Mixture ◽  
Molecular Interaction ◽  
Proton Acceptor ◽  
Single Frequency ◽  
Hydroxyl Group ◽  
Secondary Amide ◽  
Dielectric Relaxation Time ◽  
X Band ◽  
Free Hydroxyl

The secondary amide unit is a subject of particular interest, because of its occurrence in peptides and proteins. Molecular interaction between N-benzylformamide (NBF) with 1-alcohols (1-propanol, 1-butanol, 1-pentanol) has been studied in carbon tetrachloride by using X-band microwave bench at 936 GHz. Dielectric constant (ε') and dielectric loss (ε″) of alcohol and NBF and their binary mixture for different mole fractions of NBF have been determined. Dielectric relaxation time (τ) of the binary system is obtained by both Higasi's method and the Gopalakrishna single-frequency concentration variational method. The results show that the most likely interaction between alcohols and NBF is 1:1 complex for binary mixture through the free hydroxyl group of the alcohol and the carbonyl group of NBF. The alkyl chain-length of both alcohol and amide plays an important role in the determination of the strength of hydrogen bond ( O – H : C = O ) formed. The variation of relaxation time of NBF+1-alcohol mixtures in CCl 4 indicates a weak solute-solvent type of molecular association. The result shows that as the relaxation time of the proton acceptor increases, the donating ability of the solute environment increase.

scholarly journals Molecular Interactions and Dielectric Relaxation in the Mixtures of Amines with 2-Fluorobenzoic Acid in 1, 4-Dioxane

2019 ◽  
Vol 9 (1) ◽  
pp. 2866-2870
Keyword(s):  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Relaxation Times ◽  
Angular Frequency ◽  
Dielectric Constants ◽  
Intramolecular Interactions ◽  
Dielectric Parameters ◽  
Molar Ratios ◽  
Group Rotation ◽  
Static Dielectric Constants

For the present study, the estimation of the static dielectric constants (0 ), dielectric constant () at an angular frequency and dielectric loss () of methyl, ethyl and propyl amines with 2-fluorobenzoic acid in 1,4-dioxane were carried using Klystron microwave bench at frequency 9.43GHz. Using the dielectric parameters, the overall relaxation time (1 ) and group rotation relaxation time (2 ) of the polar solute molecules and average relaxation times (0 ) were also determined using Higasi and Gopalakrishna method employing Debye’s equations. The obtained results revealed that, out of five different molar ratios, relaxation time () is maximum at 1:1 molar concentration for all the systems due to inter and intramolecular interactions through hydrogen bonding. In addition, the dipole moment, activation viscous flow (f) and dielectric relaxation (f ) due to molar free energy also been discussed.

Dielectric relaxation of hydrogen—bonded complexes

1975 ◽  
Vol 9 (1-2) ◽  
pp. 205-212 ◽  
Author(s):  
E. Jakusek ◽  
M. Pajdowska ◽  
L. Sobczyk
Keyword(s):  
Dielectric Relaxation ◽  
Bonded Complexes ◽  
Hydrogen Bonded
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