scholarly journals Some Aryl-1,2,4-triazol-1-ium Phenacylids in Binary Hydroxyl Solvent Mixtures. Computational and Spectral Study

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1656
Author(s):  
Dana Ortansa Dorohoi ◽  
Dan Gheorghe Dimitriu ◽  
Ana Cezarina Morosanu ◽  
Nicoleta Puica Melniciuc ◽  
Ion Hurjui ◽  
...  
Keyword(s):  
Intermolecular Interactions ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Spectral Characteristics ◽  
Binary Solvents ◽  
Visible Range ◽  
Quantum Mechanical ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Ternary Solutions

Four carbanion monosubstituted p-aryl-1,2,4-triazol-1-ium methylids are subjected to a comparative study between their spectral and quantum-mechanical parameters in order to obtain more information about their structural features in hydroxyl solvents as water and ethanol and also on the nature of electronic absorption transitions from the visible range. The quantum mechanical analysis, made by the Spartan’14 program, established a series of molecular parameters of the studied ylids important for their reactivity and for intermolecular interactions with hydroxyl liquids. An extensive solvatochromic study of 1,2,4-triazol-1-ium ylids is impossible due to their limited solubility in liquids. Binary solvent mixtures of water and ethanol with known solvent parameters from the literature were used for this study. The electronic absorption spectra in binary solvents water and ethanol were used to establish the influence of intermolecular interactions on the spectral characteristics of the studied methylids and also on the composition of their first solvation shell in ternary solutions. The difference between the interaction energies in molecular pairs ylid–water and ylid–ethanol was determined based on the statistical cell model applied to the ternary solutions of the type of ylid + water + ethanol. The obtained values are very small due to the hydroxylic nature of the two solvents.

How intermolecular interactions influence electronic absorption spectra: insights from the molecular packing of uracil in condensed phases

2019 ◽  
Vol 21 (7) ◽  
pp. 4072-4081 ◽  
Author(s):  
Fangjia Fu ◽  
Kang Liao ◽  
Jing Ma ◽  
Zheng Cheng ◽  
Dong Zheng ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Intermolecular Interactions ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Molecular Packing ◽  
Condensed Phases

Intermolecular interactions in terms of molecular packing are crucial for the investigation of the absorption spectra of uracil in different environments.

Solubility and Thermodynamic Properties of L-Proline in Methanol-Dichloromethane Mixtures

2015 ◽  
Vol 775 ◽  
pp. 185-190
Author(s):  
Zi Dan Chen ◽  
Kun Kun Wang ◽  
Xue Li ◽  
Sheng Wang ◽  
Sha Wu ◽  
...  
Keyword(s):  
Dynamic Method ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Purification Process ◽  
Apelblat Equation ◽  
Modified Apelblat Equation ◽  
Monitoring Technique ◽  
Laser Monitoring ◽  
Hoff Equation

The solubility of L-proline in binary solvents of methanol and dichloromethane were measured by a dynamic method via a laser monitoring technique. In the binary solvent mixtures, the solubility increases with the increasing of temperature and proportion of the methanol. The experimental solubility were fitted to modified Apelblat equation and Van’t Hoff equation in this work can be used as essential data and models in the purification process of L-proline. The dissolving process is endothermic and the dissolution driving force converts from enthalpy-driving to entropy-driving.

scholarly journals SPECTRAL CHARACTERISTICS OF CONFORMATION ISOMERS OF MESO-OCTAMETHYL-CALIX(4)PYRROLE BASED ON QUANTUM-CHEMICAL CALCULATIONS

2018 ◽  
Vol 59 (5) ◽  
pp. 30
Author(s):  
Oleg V. Surov ◽  
Mikhail A. Krestianinov ◽  
Nugzar Zh. Mamardashvili
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
Quantum Chemical ◽  
Density Functional ◽  
Dynamic Equilibrium ◽  
Electronic Absorption Spectra ◽  
Spectral Characteristics ◽  
Structure Optimization ◽  
Basis Set ◽  
Functional Theory

The structure optimization and calculation of electronic absorption spectra of meso-octa-methylcalix(4)pyrrole conformers was performed  by density- functional theory using hybrid B3LYP functional in cc-pVTZ basis set of Gaussian 09 package. Analysis of experimental UV-Vis spectra of solutions of calix(4)pyrrole was carried out in various solvents. The conclusion on the existence of a dynamic equilibrium between conformers in solutions of meso-octamethylcalix(4)pyrrole was made.

scholarly journals Review of the Cosolvency Models for Predicting Drug Solubility in Solvent Mixtures: An Update

2019 ◽  
Vol 22 ◽  
pp. 466-485 ◽  
Author(s):  
Abolghasem Jouyban
Keyword(s):  
Ab Initio ◽  
Mixed Solvents ◽  
Isothermal Condition ◽  
Solubility Data ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Mathematical Form ◽  
Independent Variables ◽  
Correlative Models

The cosolvency models frequently used in solubility data modeling of drugs in mixed solvents were reviewed and their accuracies for calculating the solubility of solutes were briefly discussed. The models could be used either for correlation of the generated solubility data with temperature, solvent composition etc or for prediction of unmeasured solubility data using interpolation/extrapolation technique. Concerning the correlation results employing a given number of independent variables, the accuracies of the investigated models were comparable, since they could be converted to a single mathematical form, however, the accuracies were decreased when models emplyed more independent variables. The accurate correlative models could be employed for prediction purpose and/or screening the experimental solubility data to detect possible outliers. With regard to prediction results, the best predictions were made using the cosolvency models trained by a minimum number of experimental data points and an ab initio accurate prediction is not possible so far and further mathematical efforts are needed to provide such a tool. To connect this gap between available accurate correlative models with the ab initio predictive model, the generally trained models for calculating the solubility of various drugs in different binary mixtures, various drugs in a given binary solvent and also a given drug in various binary solvents at isothermal condition and/or different temperatures were reported. Available accuracy criteria used in the recent publications were reviewed including mean percentage deviation (MPD). The MPD for correlative models is 1-10% whereas the corresponding range for predictive models is 10-80% depend on the model capability and the number of independent variables employed by the model. This is an update for a review article published in this journal in 2008.

scholarly journals Solvatochromic Study of Two Carbanion Monosubstituted 4-Tolyl-1,2,4-triazol-1-ium Phenacylids in Binary Hydroxyl Solvent Mixtures

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3910
Author(s):  
Dana Ortansa Dorohoi ◽  
Dan-Gheorghe Dimitriu ◽  
Mihaela Maria Dulcescu-Oprea ◽  
Ana Cezarina Morosanu ◽  
Nicoleta Puica-Melniciuc ◽  
...  
Keyword(s):  
Cell Model ◽  
Solvation Shell ◽  
Solvent Mixture ◽  
Point Of View ◽  
Visible Range ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixture ◽  
Spectral Shifts ◽  
The Difference

Two 4-tolyl-1,2,4-triazol-1-ium methylids, namely 4-tolyl-1,2,4-triazol-1-ium-phenacylid and 4-tolyl-1,2,4-triazol-1-ium-4′-nitro-phenacylid, are studied from solvatochromic point of view in binary solvent mixtures of water with ethanol and water with methanol. The contributions (expressed in percent) of the universal and specific interactions are separated from the spectral shifts recorded in the visible range for each composition of the binary solvent mixture. The essential role of the orientation and induction interactions in the studied solutions was demonstrated. Based on the statistic cell model of the binary solvent mixture solutions, the difference between the formation energies of ylid-water and ylid-alcohol complexes is estimated. The composition of the ylid’s first solvation shell was also established using the model of the binary solvent mixture solutions. The results obtained from the statistical cell model were compared with those obtained by using the Suppan’s model, resulting a good agreement.

scholarly journals Stability Analysis of Binary Solvent Mixtures for Herbal Phytochemical Extraction

2017 ◽  
Vol 5 (3) ◽  
pp. 128-133
Author(s):  
Siti Nuurul Huda Mohammad Azmin ◽  
Nor Alafiza Yunus ◽  
Sharifah Rafidah Wan Alwi ◽  
Mohd Shukri Mat Nor
Keyword(s):  
Molar Fraction ◽  
Solvent Mixture ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Energy Of Mixing ◽  
Gibbs Energy Of Mixing ◽  
Extraction Processes ◽  
The Stability ◽  
Phytochemical Extraction

Most of the extraction processes of herbal phytochemicals use solvent mixtures as a phytochemical transfer mediums. It is very important to predict the stability of solvent mixtures before it is used to extract herbal phytochemicals. In order to prevent any disturbance in the herbal extraction, the solvent mixtures must be in a single liquid phase (miscible to each other). In this study, the stabilities of five binary solvents (methanol-water, methanol-ethyl acetate, methanol-acetic acid, methanol-n-propionaldehyde, and methanol-isobutyraldehyde mixtures) that could be used in the current extraction processes are evaluated. The main purpose of this study is to evaluate these binary solvents in terms of their stability using Gibbs energy of mixing. The value of the function ?Gmix/RT is calculated for each solvent mixture. Then, the graph for ?Gmix/RT versus solvent molar fraction x is plotted. From this plot and the value of function ?Gmix/RT, it can be concluded whether the solvent mixtures are stable or unstable. From the analysis, all five binary mixtures are stable within the selected molar fraction making all mixtures are suitable to be applied in herbal extraction.

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