DFT Studies and Quantum Chemical Calculations of Benzoyl Thiourea Derivatives Linked with Morpholine and Piperidine for the Evaluation of Antifungal Activity

Herein, we report the density functional study of benzoyl thiourea derivatives linked to morpholine and piperidine to evaluate their antifungal activity. Overall six compounds BTP 1-3 and BTM 4-6 were optimized with DFT using the B3LYP method with 6-31G(d,p) basis set. The molecular geometry, bond lengths, bond angles, atomic charges and HOMO-LUMO energy gap have been investigated. The structural parameters have been compared with the reported experimental results and structure- antifungal activity relationship is explored in details. The calculated results from DFT were discussed using all Quantum chemical parameters of the compounds. Introduction: Benzoyl thiourea derivatives linked with morpholine and piperidine were reported to have good antifungal activity. Objective: To find the correlations between the quantum chemical calculations and the antifungal activity for the benzoyl thiourea derivatives linked with morpholine and piperidine. Method: Optimization was carried out with DFT using B3LYP method utilizing 6-31G(d,p) basis set. Results: A good correlation between the quantum chemical calculations and the antifungal activity for the benzoyl thiourea derivatives linked with morpholine and piperidine was found. Conclusion: The DFT study of benzoyl thiourea derivatives linked to morpholine and piperidine was evaluated for their antifungal activity and it showed good correlations of activity with the quantum chemical parameters.

Inhibition of Fenton Reaction of Glucose by Alcohols and Tetrahydrofuran in Catalytic Concentrations. Calculation of the Stability Constants of ROH/Fe2+ Complexes

Background: The Fenton reaction is of growing interest due to its primary function in bodily processes and industrial waste disposal. However, the effects of alcohol on this reaction have not been addressed. Therefore, we analyze for the first time the role that catalytic concentrations of alcohols play in the Fenton reaction. Methods: The Fenton reaction was carried out by measuring oxidation-reduction potential and pH monitoring under dark conditions to avoid photochemical reactions. The reaction end point was established using the first derivative of plotting potential versus time. This point was also checked by the dichromate test for hydrogen peroxide detection. Gas-liquid chromatography was used to measure alcohol content. The Fenton reaction of glucose was performed first, and then each alcohol, including ethanol, methanol, iso-propanol, and ter-butanol, was added separately in catalytic amounts, as well as the cyclic ether tetrahydrofuran. The reaction rate constants and the stability constants of each complex formed were measured. Results : Alcohols were shown to inhibit the Fenton reaction by forming iron-alcohol complexes. An iron-tetrahydrofuran complex was also formed. The crucial oxygen role in the functional group of alcohols and ethers is supported by a reaction with tetrahydrofuran. These results also explain the difficulties in the disposal of sugar-enriched alcoholic industrial effluents. Conclusion: Our findings show that alcohols, such as ethanol, methanol, iso-propanol, and ter-butanol at catalytic concentrations, slow down the Fenton reaction due to decreased iron availability by forming iron(II)-alcohol complexes. The method is also useful for calculating stability constants for iron-alcohol and iron-tetrahydrofuran complexes, which are not otherwise easy to assess.

Applications of Flory’s Statistical Theory to Ionic Liquids in the Extended Pressure Range and at Different Temperatures

Introduction: Flory’s statistical theory (FST) for the first time, has been applied successfully to two pure ionic liquids, [C3mim][NTf2] and [C5mim][NTf2] over an extended range of pressure (0.10 – 59.9) MPa and at different temperatures (298.15 – 333.15) K . Methods: : Density and sound speed data have been employed to compute a number of useful and important properties of these ionic liquids in the light of FST. Using Flory parameters (P*, T*, V*, P̃, T̃, Ṽ) the expression for the surface tension (σ) has been deduced in the form σ = σ* σ᷉ (Ṽ), σ* and σ᷉ (Ṽ) being the characteristic and reduced values of surface tension. Since the experimental σ of liquids is not known, the validity of FST has been tested by calculating u using four different u-ρ- σ correlations, namely Auerbach (1948), Altenberg (1950) Singh et al (1997) and Modified Auerbach (2016). Results: A number of useful and important properties of ionic liquids, under the varying physical conditions, have been deduced and compared with the observed ones with quite satisfactory agreement. Such properties include Pint, van der Waals constants (a & b), parachor [P], Eötvas constant (kB), energy (∆EV) and heat of vaporization (∆HV), cohesive energy density (ced), polarity index (n) and solubility parameter (δ). Conclusion: Thus the validity of FST to two ionic liquids under the present study, has been confirmed.

Accurate Assessment of Joule-Thomson Inversion Temperature at Zero Pressure of Imperfect Gases

Background: The aim of this work is to propose an approach for estimating the Joule-Thomson coefficient as an important parameter necessary to the study of changes in fluid temperature at a given change in pressure at constant enthalpy. Objective: The analytical approach presented in this work is very appropriate for detailed studies of the Joule-Thomson inversion temperature at zero pressure for arbitrary temperature values. Methods: A new approach is suggested for the accurate determination of the Joule-Thomson inversion temperature at zero pressure using the virial coefficient of the Lennard-Jones (12-6) potential. Results: The usefulness and efficiency of the method are tested by application to various gase Ar, He,Ne,H2,O2,CO2CO,CH4,Xe, Kr,N2 and Air. The results obtained are in good agreement with other approximation and experimental data. Conclusion: The suggested formula enables correct and rapid calculation of the JT inversion temperature at zero pressure.

Non-Covalent interaction between Ionic liquid (1-ethyl-3-methylimidazolium chloride-aluminum chloride) and pure alcohols

Background: The non-covalent molecular interactions of 1-Ethyl-3-methylimidazolium chloride-aluminum chloride and pure alcohols attract attention in the industry, academic and research. Chemists, engineers, designers, and some researchers are much interested in the accessibility of its trustworthy databases. Objective: 1-Ethyl-3-methylimidazolium chloride-aluminum chloride is interacting with pure alcohols with non-covalent interactions. Physicochemical properties with their convincing data interpreting the interactions occurring there. Mehtods: For that limiting apparent molar volume, molar refraction, and limiting apparent molar isentropic compressibility of the binary systems viz., ([EMIm]Cl/AlCl3) +methanol, ([EMIm]Cl/AlCl3) +ethanol, ([EMIm]Cl/AlCl3) +1-propanol, and ([EMIm]Cl/AlCl3)+1-butanol have been calculated using physicochemical properties i.e.,. density, refractive index, and speed of sound, respectively, within the temperature range T=293.15K-318.15K (with the interval of 5K). Results: The ionic liquid strongly interacts with 1-butanol (106ϕ_v^o=874.52 m3 mol-1, 106•RM = 211.13 m3 mol-1, and 10-11•ϕ_k^o= -0.10 m3 mol-1 Pa-1, 108•((〖∂ϕ〗_E^o)⁄∂T)_p = 1.52 m3 mol-1 K-2) than other chosen primary alcohol at a higher temperature (318.15K). Among individual ions, the 106•ϕ_(V(ion))^o is higher for 〖AlCl_(4 )〗^-(522.96 m3 mol-1) than [EMIm]^+(351.56 m3 mol-1) at high temperature (318.15K) in 1-butanol. Conclusion: The molecular interactions occurring between the ionic liquid and solvent molecules are due to the structure-making capacity that causes by intermolecular forces and non-covalent interactions. Where, the 1-butanol strongly interact with ionic liquids. In beween the ions, the anaion interaction is greater than cation to solvents.

Anticorrosive properties of theophylline on aluminium corrosion in 1M HCl: Experimental, Computational assessment and synergistic effect iodide ions

Aims : The aim of this study is to show the anticorrosive properties of 1,3-dimethyl-7H-purine-2,6-dione on aluminium corrosion in 1M hydrochloric acid and to study the synergy effect between iodide ions and this molecule. Background: Research of eco-friendly, low toxic and biodegradable corrosion inhibitors capable of protecting metals in order to support industrialists who spend large sums of money to replace their corroded equipment. Objective: The main objective is to study the anticorrosive properties of theophylline on aluminium corrosion in 1M HCl. Methods: The anticorrosive properties study of theophylline on aluminium corrosion in 1M HCl was evaluated using mass loss, Density Functional Theory at B3LYP/6-31G (d) and Quantitative Structure-Property Relationship methods. Results: The results obtained show that theophylline inhibition efficiency increases with concentration but decreases with increasing temperature with a maximum value of 88% for 5.10-3M at T = 298 K. The result from absorption isotherms reveals that theophylline adsorbs to the aluminium surface according to the modified Langmuir isotherm. Adejo Ekwenshi's isotherm has shown that the molecule adsorption on aluminium is essentially of a physical nature. Thermodynamic adsorption and activation parameters were calculated and analyzed. A synergistic effect between the molecule studied and the iodide ions was found. Furthermore, global and local reactivity were analyzed through density functional theory calculations. Quantitative structure-property relationship methods model has been permitted to correlate experimental and theoretical inhibition efficiencies. Conclusion: Theophylline is an excellent aluminum inhibitor corrosion in the studied solution. Theoretical results were in agreement with experimental data. Other: Finally to find the best set of parameters for modeling the inhibition efficiency.

Kinetic Study of Iodination of Propanone in Different Acidic Medium by using Colorimeter

Aims: This study aims at the Kinetic Study of Iodination of Propanone in Different Acidic Medium by using Colorimeter. Background: The kinetic experimentation of iodination of propanone has been performed in presence of different acids such as sulphuric acid, hydrochloric acid and acetic acid. The rate law of the iodination of propanone in acidic medium is determined by observing the disappearance of the brownish yellow colour of iodine in aqueous solution. Objective: The objective of this study is the preparation of standard solution, determination of absorbance of iodine solution at λmax= 480 nm, Kinetic study of iodination of propanone with different acidic medium. Method: The kinetic analysis of this reaction has been carried out by colorimetry. The extent of the reaction has been monitored by measuring the absorbance of the reaction mixture after a suitable time interval. Result: The rate law expression is determined to be rate = k [〖"propanone]" 〗_0^0.728 [acid]0. The rates of iodination of propanone in presence of different acidic medium are H2SO4 > HCl > CH3COOH. Conclusion: The rate of the reaction is found to be independent of the concentration of iodine i.e. it is zero order reaction with respect to iodine. However, it depends on the concentration of propanone and acid catalyst. Other: By using this experimental technique, the consumption of chemicals is very less.