[1] |
Solvation model, Vibrational analysis, Electronic level, Non-Covalent interactions and Molecular docking investigations of 6-Chloro-2-(4-Aminophenyl)-1H-Benzimidazole G.S Fasiuddin In Journal of Molecular Liquids, Elsevier LTD, Mar 2024, Volume: 398, Page: 124315.
Abstract [+]
6-Chloro-2-(4-Aminophenyl)-1H-Benzimidazole compound were synthesized and characterized by SC-XRD, FT-IR, FT-Raman, UV–Vis, 1H NMR, and 13C NMR and analyzed with experimental data. The DFT approach with the B3LYP functional and 6-311++G(d,p) basis set was used to calculate the geometry parameters and wavenumbers of the title compound. Electronic absorption spectra and 1H–13C NMR studies have been computed in gas and solvents (dimethylsulfoxide, chloroform, and H2O) by using the TD-DFT and the IEFPCM solvation model. The HOMO-LUMO energy band gap has also been determined. To identify the electron localization density and weak interactions, the Multiwin-3.8 was subjected to a topological analysis and non-covalent interactions, including ELF, LOL, DORI and ED. Studies of donor–acceptor connections were performed using NBO analysis. To calculate contributions to the molecular orbitals, TDOS was determined. Molecular electrostatic potential (MEP) reveals the chemical reactivity sites for the reaction. The antibacterial activity of the compound has been assessed with a zone of inhibition by the well diffusion method using a panel of selected gram-positive Staphylococcus aureus (MTCC-3160), Enterococcus faecalis (MTCC-3159) and gram-negative Pseudomonas aeruginosa (MTCC-4030), Escherichia coli (MTCC-1667) bacterial strains that have shown better activity than the standard drug (Ciprofloxacin). Finally, molecular docking and pharmacokinetics have been agreed upon to understand the binding energy of the ligand–protein interaction.
|
[2] |
Exploring High-Performance Functionalized Corannulene Dimers: A DFT-Based Investigation for Novel Photovoltaic Applications Hamid Hadi In Synthetic Metals, Elsevier Ltd, Feb 2024, Volume: 302, Page: 117543.
Abstract [+]
Our current research is focused on designing new corannulene derivatives that exhibit significantly improved photovoltaic characteristics. These improvements comprise reduced excitation energy, a narrower optical band gap, enhanced light absorption capabilities, a high dipole moment, and reduced reorganization energies. Theoretical calculations of these parameters could pave the way for the creation of superior molecules for use in advanced solar cell technologies. In this work, we conducted a computational study (TD-DFT/CAM-B3LYP/6–311 +G) to examine the optical and electronic characteristics of a series of short-chain materials derived from a central core-based corannulene (A, B, C, D, and E-systems). The effect of various electron-donor side groups (such as: (1) 4-di(2-thienyl) thieno[3,4][1,2,5]-thiadiazole, (2) 2,2-Methyl Cyclopenta dithiophene, (3) Cyclopenta dithiophene, (4) 3,4-ethylene dioxythiophene, and (5) 4,6-di(2-thienyl)thieno[3,4-c][1,2,5]-thiadiazole (DTTTD)) on the electronic and photovoltaic properties of corannulene derivative as an electron-acceptor (such as radiation lifetime (τ), light harvesting efficiency (LHE), and maximum open circuit voltage (Voc)) was studied computationally. Also, the electron localization function (ELF) and the localized-orbital locator (LOL) analyses are used to discover the electronic localizations and delocalizations that occur after the addition of various ligands. The electronic and photovoltaic properties of each of the designed molecular structures were compared with P3HT as a reference. The obtained results showed that each of the designed molecular structures (especially the D-structure) is very efficient in the field of photovoltaics. Therefore, it seems that the D-structure can act (as a more suitable electron-donor than P3HT) together with phenyl-C61-butyric acid methyl ester (PC61BM) (as a good electron-acceptor) and improve the efficiency of solar cells.
|
[3] |
Investigations into the anti-inflammatory and anti-diabetic activity of newly synthesized derivatives of 4AP2BOB utilizing DFT, molecular docking and spectroscopic characterization M Selvakumaran In Journal of Molecular Liquids, Elsevier Ltd, Feb 2024, Volume: 396, Page: 123983.
Abstract [+]
Utilizing cutting-edge spectroscopic techniques, including FT-IR, 1H NMR and 13C NMR, we created and thoroughly evaluated novel forms of Acetamidophenyl-2-(benzoyloxy) benzoate. This study is coupled with the reduction of COX1, COX2 and alpha-amylase which are associated with diabetes and inflammation and that have shown encouraging outcomes in laboratory studies. The molecular structures of the title compound, , its vibrational frequencies and corresponding vibrational assignments have been investigated experimentally. Additionally, over the cube files of the molecule, FMO and MEP analyses were performed. Further, in-silico ADME research on the newly developed compounds was also done. Finally, the molecular docking calculations and in-depth drug-likeness profiling were conducted according to empirical rules related to ADME to validate the conclusions and designate precise binding interactions. Considering the findings of the study, it has been established that these novel compounds offer a great deal of promise as potent therapeutic agents for managing inflammation and diabetes.
|
[4] |
Design, Transport/Molecular Scale Electronics, Electric Properties, and a Conventional Quantum Study of a New Potential Molecular Switch for Nanoelectronic Devices Hamid Hadi In ACS Omega, ACS Publications, Jan 2024, Volume: 9(1), Page: 1029–1041.
Abstract [+]
In this study, we examined the influence of an external electric field applied in two directions: horizontal (X-axis) and vertical (Y-axis) on the electronic and vibrational properties of a field-effect molecular switch, denoted as M. We employed density functional theory and quantum theory of atoms in molecules for this analysis. The current–voltage (I–V) characteristic curve of molecular switch system M was computed by applying the Landauer formula. The results showed that the switching mechanism depends on the direction of the electric field. When the electric field is applied along the X-axis and its intensity is around 0.01 au, OFF/ON switching mechanisms occur. By utilizing electronic localization functions and localized-orbital locator topological analysis, we observed significant intramolecular electronic charge transfer “back and forth” in Au–M–Au systems when compared to the isolated system. The noncovalent interaction revealed that the Au–M–Au complex is also stabilized by electrostatic interactions. However, if the electric field is applied along the Y-axis, a switching mechanism (OFF/ON) occurs when the electric field intensity reaches 0.008 au. Additionally, the local electronic phenomenological coefficients (Lelec) of this field-effect molecular switch were determined by using the Onsager phenomenological approach. It can also be predicted that the molecular electrical conductance (G) increases as Lelec increases. Finally, the electronic and vibrational properties of the proposed models M and Au–M–Au exhibit a powerful switching mechanism that may potentially be employed in a new generation of electronic devices.
|
[5] |
Exploring the antiviral potency of γ-FP and PA compounds: Electronic characterization, non-covalent interaction analysis and docking profiling with emphasis on QTAIM aspects A Aathif Basha In Computational and Theoretical Chemistry, Elsevier Ltd, Jan 2024, Volume: 1231, Page: 114412.
Abstract [+]
As focuses on a set of pertinent compounds that incorporate a γ-substituted halophenol linkage with pentanamide (PA). The properties of these compounds were comprehensively assessed through various analytical techniques, including density functional theory (DFT) calculations, offering insights into their geometry and electronic energy gap characteristics. Charge delocalization and stability were explored via natural bond orbital (NBO) analysis. The chemical reactivity was further scrutinized by evaluating NBO, Molecular Electrostatic Potential (MEP), Hirshfeld surface analysis and Fukui functions. The compounds were found to exhibit stability attributed to a robust hydrogen bonding network, which was corroborated by Interaction Region Indicator (IRI) and Electron Density (ED) assessments. Additionally, pharmacological properties were predicted using the PASS (Prediction of Activity Spectra for Substances) server. Molecular docking studies suggested potential antiviral and antioxidant properties, particularly concerning carbonic anhydrase. The overall results imply that these compounds possess favorable drug-like characteristics and show promise for biological efficacy. The study also includes a 2D interaction profile image of the four most interacted proteins and a Ramachandran plot to elucidate the stereochemistry of a selected protein. Furthermore, the activities of 6FDM were investigated following a comprehensive literature survey, with detailed findings presented.
|
[6] |
Chelation Agent As Potential Target Antioxidant: DFT, Physicochemical Properties, Topological Analysis, and Molecular Docking Studies into Intramolecular Interactions Attar Kubaib In Russian Journal of Physical Chemistry A, Springer Nature, Dec 2023, Volume: 97, Page: 2884-2893.
Abstract [+]
The electronic characterization of monomer and dimer molecule’s C6H6O4 was also calculated using the DFT (B3LYP/6311G++(d,p)) method. The calculated TDOS, HOMO, and LUMO were performed through intramolecular charge transfer to investigate the molecule’s stability. In dimethylsulfoxide (DMSO), the UV spectrum has been determined. According to Swiss-ADME, Aspergillus oryzae is not mutagenic or carcinogenic. Additionally calculated were the Mulliken charges, Fukui indices and MEP. Swiss-ADME was used to forecast predictions and significant descriptors of the compounds’ physicochemical characteristics. The intermolecular interactions were examined using topological analysis techniques like RDG and IRI. For the 1JNK Protein, Aspergillus oryzae has a binding affinity of –6.21.
|
[7] |
Ternary Mixture of Pentanamide in Solvent Analogy with Halogenated Phenol: Experimental, Theoretical, and In Silico Biological Studies A. Aathif Basha In ACS Omega, ACS Publications, Sep 2023, Volume: 8, Page: 33928-33942.
Abstract [+]
This research describes the preparation of mixtures of new halogen-substituted phenol derivatives and their effects due to linkages with a fatty amide (pentanamide). The molecules were optimized using DFT, and the vibrational and electronic analysis was done subsequently. The energies of frontier molecular orbitals (FMOs) were used to estimate the global chemical reactivity parameters as we suggest that hydrogen-bonded networks may have contributed to the stability and reactivity of the compound. In addition to the experimental investigation, dielectric parameters were calculated. Fukui functions were analyzed to study the chemical reactivity. To get insight into interactions of σ → π* orbitals, natural bond orbital calculations were done. Additionally, surface analysis of the MEP and Hirshfeld charges were performed at the equivalent DFT levels. The research also indicated that both (interaction region indicator) IRI and (electron delocalize range) EDR would proficiently identify chemical-bonding and weak interaction regions, providing a significant advantage in exploring diverse chemical systems and reactions. This indicated that compounds could diffuse through noncovalent interactions, including intramolecular hydrogen bonding. Dielectric relaxation studies taken at five distinct molar ratios identified significant dielectric properties such as ε′, ε″, ε0, and ε∞. The PA with FP, CP, BP, and IP molecules has potential antiviral and antioxidant benefits for carbonic anhydrase, with favorable drug-like features and diverse biological benefits. Pharmacological effects were forecasted using the PASS server, and these molecules exhibited favorable pharmacokinetic properties.
|
[8] |
Dielectrics relaxation studies of acrylamide and acetanilide with halogenated phenols in benzene A. Aathif Basha In AIP Publishing, AIP CONFERENCE PROCEEDINGS, May 2023, Volume: 2492, Page: 050001-6.
Abstract [+]
At 308 K, using a 9.37 GHz dielectric relaxation setup, dielectric investigations of H-bonded formations of Acrylamide and Acetanilide with 4-bromophenol, 4-chlorophenol, 4-iodophenol and 4-fluorophenol in benzene were performed. Various parameters of dielectric like (ε׳), (ε״), (ε0) and (ε∞) have been tested. The group rotation relaxation time τ(2) is a function of the steric interactions of the proton donor, while the significance of Higasi et al single frequency equation used for few relaxation times τ(1) is creates towards a role of the hydrogen bonding power of the phenolic hydrogen. The fact that the relaxation time and molar free energy activation of the 1:1 molar ratio are bigger than those of additional superior molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirms the presence of a 1:1 complex structure among the considered structures, as well as a complex formation in the middle of the -OH group of phenols and the C=O group of amides
|
[9] |
Valeramide and halo-phenol in a non-polar liquid: DFT based characterization and reactivity, non-covalent interaction, and dielectric relaxation studies A Aathif Basha In Polycyclic Aromatic Compounds, Taylor & Francis, Jan 2023, Volume: 1, Page: 1-26.
Abstract [+]
Valeramide and halogenated phenol in solvent benzene have been studied using DFT. Dielectric relaxation studies have also been undertaken. The wave functional characteristics like reduced density gradient (RDG), electron localization function (ELF), localized orbital locator (LOL) are also evaluated. It has been found that the computed FMO energies accurately depict the characteristics of electron excitation which provide an explanation for the charge transfer. MEP analysis is done to identify electrophilic and nucleophilic sites. The theoretical analysis of the UV-Visible spectrum using the TD-DFT method in solution and the computational investigation of spectroscopic wavenumbers was also carried out (IR, Raman). Thermodynamic properties of title compound at different temperatures was carried out. Various dielectric parameters, like the dielectric constant
ε′, the dielectric loss ε″ at microwave frequency, the static dielectric constant ε0 and the dielectric constant ε∞ at optical frequency, were measured across five distinct molar ratios (i.e. 1:3, 1:2, 1:1, 2:1 and 3:1). While the relaxation time τ2 for group rotation is utilized to identify the steric interaction of the proton donor, Higasi’s single-frequency equation is proven to measure multiple relaxation time τ1 to determine the intensity of hydrogen bonding. At a 1:1 (molar ratio) , the values of relaxation time were found to be high. Molecular docking was done in a supplementary effort to support intermolecular interactions.
|
[10] |
Dielectric relaxation, dipole moment, electronic characterization and non-covalent interaction behavior of valeramide and halo-phenol in non-polar liquid: A density functional theory-based approach A. Aathif Basha In Journal of Molecular Liquids, Elsevier LTD, Dec 2022, Volume: 370, Page: 121027.
Abstract [+]
In the present work, DFT has been used to explore the structural, electronic, charge transfer and molecular interactions between valeramide and halogenated phenol in solvent benzene and Dielectric relaxation studies have also been used. The optimized geometrical parameters, wavefunctional characteristics like a reduced density gradient, chemical bonds and the electron localization function are reported. It has been discovered that the HOMO and LUMO computed energies accurately depict the characteristics of electron excitation. MEP analysis is used to identify electrophilic and nucleophilic sites. The analysis of the UV–visible spectrum using the TD-DFT method with solutions and the computational investigation of spectroscopic wavenumbers (IR, Raman). The study of natural bond orbitals is carried out to provide an explanation for the charge transfer and stabilization energy resulting from current intra- or intermolecular interactions. Dipole moments of the pure liquids are calculated from the dielectric data using Higasi’s method and compared with the literature results. Various dielectric parameters are given, including the dielectric constant ε′, the dielectric loss ε′′ at microwave frequency, the static dielectric constant ε0 and the dielectric constant ε∞ at optical frequency. The different parameters of dielectric, relaxation time (τ0) and the dipole moment (μ) has been evaluated using the single-frequency concentration Higasi’s method. The fact that the relaxation time of the 1:1 M ratio are greater than those of other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirms the presence of a 1:1 complex structure between the studied systems, as well as a complex formation between the free hydroxyl group of phenols and the carbonyl group of amide.
|
[11] |
Applications of the Vienna Ab initio simulation package, DFT and molecular interaction studies for investigating the electrochemical stability and solvation performance of non-aqueous NaMF6 electrolytes for sodium-ion batteries Attar Kubaib In Computational and Theoretical Chemistry, Elsevier LTD, Nov 2022, Volume: 1217, Page: 113934.
Abstract [+]
his work uses a DFT-based method to compute the molecule's reduction and oxidation potentials to determine electronic association and provides high accuracy results when comparing the electrochemical stability in an electrolyte's with experimental data. The sodium electrolytes were ordered based on the determined electrochemical potentials of the PF-6 anion and Na+ cation interactions with carbonates. Since EC and EMC are more dominating than DMC and DEC according to the data, the solvent solvation model is represented for further investigations as a mix combination. Following research, we get comparable sodium-based electrolytes with similar reactivity that are similar in activity to sodium hexafluorophosphate (NaPF6). Often, variables including free energy, chemical potential, frontier molecular orbitals, molecular electrostatic potential (MEP), hardness, softness, electronegativity and electrophilicity score are used to illustrate the relationship between the stability, redox potential, chemical reactivity and corrosion inhibition of electrolyte analogues. The good solubility in carbonates and chemically active sodium-based electrolytes has been discussed. Using VASP, the optical data of NaPF6 was investigated and band structure and DOS analysis were used to identify and correlate the experimental band gap values. The appropriate delineation of the performance of quantum chemistry simulations to investigate the electronic characteristics, as well as their synthesis scheme and FT-IR characterization of a few electrolyte.
|
[12] |
Dielectric relaxation and dipole moment studies of hydrogen bonded complexes for enanthamide and valeramide with halogenated phenols using J-band microwave frequency A Aathif Basha In IOP Science , IOP Publishing, Jul 2022, Volume: 9 075303, Page: 1-11.
Abstract [+]
Dielectric investigations of hydrogen bonded complexes of Enanthamide and Valeramide with 4-bromophenol, 4-chlorophenol, 4-iodophenol and 4-fluorophenol in benzene were done at 303K, using a J-band (7.22GHz) microwave bench and dielectric relaxation setup. The permittivity of amides
with halogenated phenol binary mixtures was measured in the microwave frequency range at temperatures ranging from 298K to 323K. At microwave frequencies; dielectric relaxation of ternary mixes of polar liquids in nonpolar fluids has been explored. Such investigations give useful information about the intermolecular and intramolecular interactions of solutes and solvent molecules. The dipole meter had a measurement frequency of 2MHz. The different parameters of dielectric, relaxation time (τ0 ) and the dipole moment (μ) has been evaluated using the single frequency concentration Higasi approach. The fact that the relaxation time and molar free energy activation of the 1:1 molar ratio are greater than those of other higher molar ratios(i.e. 3:1, 2:1, 1:2, 1:3) confirms the presence of a 1:1 complex structure between the studied systems, as well as a complex formation between the free hydroxyl group of phenols and the carbonyl group of amides. The dielectric relaxation energy parameters(ΔFε, ΔHε and ΔSε) of amides with halogenated phenols in benzene have been computed and compared with the related viscosity parameters. A comparison of these two sets of characteristics reveals that dielectric relaxation, like viscous flow, may be thought of as rate process.
|
[13] |
Dielectric relaxation and thermodynamical parameters of hydrogen bonded complexes for Heptanamide and Pentanamide with halogenated phenols in benzene A. Aathif Basha In Journal of Molecular Liquids, Elsevier LTD, Jul 2022, Volume: 363, Page: 119853.
Abstract [+]
In the experiment and dielectric relaxation setup at 303 K, X-band (9.34 GHz) and J-band (7.22 GHz) microwave benches were employed. In benzene, dielectric experiments were done on hydrogen-bonded complexes of Heptanamide and Pentanamide with 4-bromophenol, 4-chlorophenol, 4-iodophenol, and 4-fluorophenol. Microwave dielectric spectra for binary mixtures of alkanamides with Halogenated phenols have been determined over the frequency range of 10 MHz to 20 GHz at 303 K. Dielectric properties such as (ε׳), (ε''), (ε0) and (ε∞) have been investigated. The geometries are optimized at B3LYP with 6-311G++ basis set. Dipole moments of the binary mixtures are calculated from the dielectric data using Higasi’s method and compared with the theoretical results. The relaxation periods (τ0) for ternary liquid combinations were measured using Higasi's approach. According to the ternary data, the relaxation time is highest for 1:1 complexes. According to the system under examination, the relaxation time value increases as the concentration of solute increases. For various ternary mixes and molecular conformations of these systems, the relaxation periods (τ0) of the two bands are compared. The dielectric relaxation energy parameters of thermodynamics (ΔFε, ΔHε, ΔSε) of amides with halogenated phenols in benzene were calculated and compared to the associated viscosity parameters.
|
[14] |
Relaxation in dielectric studies, hydrogen bonded complexes of hexanamide and octanamide with 4-halophenols using X and J-bands microwave frequency A. Aathif Basha In Materialstoday:Proceedings, Elsevier Ltd, Apr 2022, Volume: 57, Page: 2364-2371.
Abstract [+]
At 303 K, X-band (9.34 GHz) and J-band (7.22 GHz) Microwave benches were used in the experiment and dielectric relaxation setup, dielectric studies of hydrogen bonded complexes of Hexanamide and Octanamide with 4-bromophenol, 4-chlorophenol, 4-iodophenol and 4-fluorophenol in benzene were performed. Various parameters of dielectric like (ε׳), (ε), (ε0) and (ε�) have been carried out. Higasi's approach was used to measure the relaxation times (�0) for ternary liquid combination. The relaxation time is shown to be greatest for 1:1 complexes based on the ternary data. Our findings also show that the molar free energy of activation for viscous flow (�Fη) is bigger than the free energy activation for relaxation time (�F�). The system under investigation indicates that the relaxation time value increases as the concentration of solute increases. The relaxation times (�0) of the two bands (X-Band and J-Band) for various ternary mixtures molecular conformations of these systems are compared.
|
[15] |
Dielectric Relaxation Studies of Hydrogen Bonded Complexes of Benzamide and Acetamide with Halogenated Phenols Using X-band Microwave Frequency A. Aathif Basha In ASEAN Journal on Science & Technology for Development, Universitas Gadjah Mada, Dec 2021, Volume: 38, Page: 125-130.
Abstract [+]
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 ϵ′ , ϵ′′ , ϵ0, ϵ∞) were tested. The steric interactions of the proton donor determined the group rotation relaxation time τ(2), whereas the significance of the single frequency method of Higasi et al. for multiple relaxation time τ(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).
|
[16] |
DIELECTRIC RELAXATION STUDIES OF ACETATES WITH PHENOL DERIVATIVES IN CCL4 A. Parthiban In International Journal of Science and Humanities, Islamiah College(Autonomous), Jun 2021, Volume: 7, Page: 184-194.
Abstract [+]
The dielectric relaxation of acetates (methyl acetate, ethyl acetate and butyl acetate) with phenol derivates (p-chlorophenol,p-iodophenol and p-nitrophenol) has been measured at 9.37 GHz using microwave Frequency in dilute solution of carbon tetrachloride at 308K. Different dielectric parameters like dielectric constant (ε׳), dielectric loss factor (ε״) at Microwave frequency, static dielectric constant (ε0) and dielectric constant at infinite dilution (ε∞) at optical frequency have been determined. From the measured dielectric data, the relaxation time () calculated using Higasi method and activation energies (∆F and ∆Fη) have been determined. The relaxation time and molar free energy activation of 1:1 molar ratio is greater than other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirm that the existence of most likely 1:1 complex formation between the studied systems and also complex formation formed between free hydroxyl group of phenol and carbonyl group of acetate.
|
[17] |
DIELECTRIC RELAXATION STUDIES OF ACRYLAMIDE WITH GLYCOLS IN NON-POLAR SOLVENTS USING FREQUENCY DOMAIN TECHNIQUE A. Aathif Basha In International Journal of Science and Humanities, Islamiah College(Autonomous), Dec 2020, Volume: 6, Page: 1-8.
Abstract [+]
The dielectric relaxation of Glycols (ethylene glycol, diethylene glycol and triethylene glycol) with Acrylamide in dilute solution of Benzene and 1,4-diaxone is measured at 9.37 GHz using Frequency domain (X-band) technique. Different dielectric parameters like dielectric constant (ε׳), dielectric loss factor (ε״) at Microwave frequency, static dielectric constant (ε0) and dielectric constant at infinite dilution (ε∞) at optical frequency have been determined. From the measured dielectric data, the relaxation time () calculated using Higasi method and activation energies (∆F and ∆Fη) have been determined. The relaxation time and molar free energy activation of 1:1 molar ratio is greater than other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3) confirm that the existence of most likely 1:1 complex formation between the studied systems and also complex formation formed between free hydroxyl group of glycols and carbonyl group of amide.
|
[18] |
DIELECTRIC RELAXATION STUDIES OF MOLECULAR ASSOCIATION: COMPLEXING OF ALKYL METHACRYLATES WITH PHENOL DERIVATIVES IN THE MW REGION Dr. F. LIAKATH ALI KHAN In International Journal of Science and Humanities, Islamiah college(Autonomous), Dec 2017, Volume: 3, Page: 139-148.
Abstract [+]
Dielectric relaxation measurements on alkyl methacrylates (methyl methacrylate, ethyl methacrylate and butylmethacrylate) with phenols (p-cresol, pchlorophenol, 2, 4-dichlorophenol and p-bromophenol) have been studied at microwave frequency 9.37 GHz in dilute solution of carbon tetrachloride at 308K. Different dielectric parameters like dielectric constant (ε׳) and dielectric loss (ε״) at microwave frequency, static dielectric constant(ε0) and dielectric constant (ε�) at optical frequency have been determined. The relaxation time and activation energy have been determined using the measured dielectric data. The results show a linear dependence of relaxation time on alkyl chain length of acrylic esters and acidity ofphenols and also on the nature of the solvent. Comparative study of free energy of activation for the dielectric relaxation and viscous flow suggest the fact that the process of viscous flow involves greater inference by neighboring than does dielectric relaxation, as the latter takes place by rotation only whereas the viscous flow involves both the rotational and translational forms of motion. The validity of the single frequency equation of Higasi et al. for multiple relaxation time(1) is found to be function of the hydrogen bonding strength of phenolic hydrogen whereas the group rotation relaxation time �(2) is a function of the steric interaction of proton donor. The relaxation time is �(0) maximum at 50:50 mol% ratio.
|