Influence of solvent effect on polymorphism of 4-hydroxy-2-methyl-N-2-pyridyl-2H-1,2-benzothiazine-3-carboxamide-1, 1-dioxide (piroxicam)

1991 ◽  
Vol 21 (4) ◽  
pp. 519-522 ◽  
Author(s):  
M. Janik ◽  
Z. Malarski ◽  
J. Mrozińiski ◽  
J. Wajcht ◽  
Z. Zborucki
Keyword(s):  
Solvent Effect ◽  
Influence Of Solvent

scholarly journals Valence tautomerism and recyclisation of type B mesoionic tetrazoles: a computational study

2021 ◽  
Author(s):  
Wojciech Piotr Oziminski ◽  
Christopher Antony Ramsden
Keyword(s):  
Solvent Effect ◽  
Ring Opening ◽  
Continuum Model ◽  
Computational Study ◽  
Reaction Pathway ◽  
Type B ◽  
Valence Tautomerism ◽  
Energy Profiles ◽  
Aqueous Solvation ◽  
Influence Of Solvent

AbstractThe energy profiles for ring opening of representative type B mesoionic 2,3-diphenyl-1,2,3,4-tetrazolium-5-olates, -thiolates, -aminides and –methylides and for alternative recyclisation pathways are investigated using ab initio MP2 calculations. The energetics of initial ring opening are found to be comparable for all systems, but the tetrazolium-5-olates are anomalous in that no alternative reaction pathway is accessible. The influence of solvent is explored using the polarised continuum model (PCM) method to simulate aqueous solvation. The only significant solvent effect is found to be solvation of the mesoionic precursors. This solvent effect correlates with dipole moment and disfavours initial valence tautomerism both kinetically and thermodynamically.

Kinetic Solvent Effects in Organic Reactions

2017 ◽  
Author(s):  
Belinda Slakman ◽  
Richard West
Keyword(s):  
Solvent Effect ◽  
Reaction Kinetics ◽  
Computational Methods ◽  
High Throughput ◽  
Kinetic Modeling ◽  
Solvent Effects ◽  
Reaction Rates ◽  
Prior Work ◽  
Solvent Phase ◽  
High Throughput Manner

<div> <div> <div> <p>This article reviews prior work studying reaction kinetics in solution, with the goal of using this information to improve detailed kinetic modeling in the solvent phase. Both experimental and computational methods for calculating reaction rates in liquids are reviewed. Previous studies, which used such methods to determine solvent effects, are then analyzed based on reaction family. Many of these studies correlate kinetic solvent effect with one or more solvent parameters or properties of reacting species, but it is not always possible, and investigations are usually done on too few reactions and solvents to truly generalize. From these studies, we present suggestions on how best to use data to generalize solvent effects for many different reaction types in a high throughput manner. </p> </div> </div> </div>

Isotope solvent effect on the hydrogenation of maleic acid

1978 ◽  
Vol 43 (7) ◽  
pp. 1832-1837
Author(s):  
Rostislav Kudláček ◽  
Josef Cabicar ◽  
Milan Buňata
Keyword(s):  
Solvent Effect ◽  
Maleic Acid

Solvent effect on valence vibration of NH bond of acetanilides and phenylcarbamates

1976 ◽  
Vol 41 (2) ◽  
pp. 430-432
Author(s):  
V. Bekárek ◽  
J. Jirkovský ◽  
K. Pragerová ◽  
J. Socha
Keyword(s):  
Solvent Effect ◽  
Valence Vibration

On the conformational structure of nicotinamide and methyl-1,4-dihydronicotinamide

1979 ◽  
Vol 44 (9) ◽  
pp. 2633-2638 ◽  
Author(s):  
Hans-Jörg Hofmann ◽  
Josef Kuthan
Keyword(s):  
Molecular Structure ◽  
Continuum Model ◽  
Model Analysis ◽  
Wave Functions ◽  
Conformational Structure ◽  
Influence Of Solvent

The conformation of nicotinamide (I) and 1-methyl-1,4-dihydronicotinamide (II) was examined using the NDDO method. The influence of solvent on the molecular structure of the title compounds was estimated by means of a continuum model. Analysis of the NDDO wave functions contributes to the knowledge about the mechanism of the NADH reduction.

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

Additive-multiplicative description of extrathermodynamic relations: Application to solvent effect

1990 ◽  
Vol 55 (3) ◽  
pp. 634-643 ◽  
Author(s):  
Oldřich Pytela
Keyword(s):  
Solvent Effect ◽  
Additive Model ◽  
Multiplicative Model ◽  
Data Matrix ◽  
Statistical Parameters ◽  
Model Application ◽  
Mutual Correlation ◽  
Linear Free Energy ◽  
Cross Terms ◽  
Energy Relationships

The paper is focused on evaluation of significance of the additive-multiplicative model of extrathermodynamic relations (linear free energy relationships) as compared with the additive model. Application of the method of conjugated deviations to a data matrix describing manifestations of solvent effects in 367 processes in solutions (6 334 data) has shown that introduction of cross-terms into the additive model is statistically significant for a model with two and particularly three parameters. At the same time the calculation has provided a new set of statistical parameters for description of solvent effect with application of the additive-multiplicative model. Compared with an analogous set designated for the additive model, the new parameters show a lower mutual correlation, retaining the same nature of the properties described, i.e. polarity-acidity (PAC parameter), polarity-basicity (PBC), and polarity-polarizability (PPC).

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