scholarly journals Group Contribution Methods for Estimation of Selected Physico-Chemical Properties of Organic Compounds

10.5772/49998 ◽  
2012 ◽  
Author(s):  
Zdenka Kolska ◽  
Milan Zabransky ◽  
Alena Randov
Keyword(s):  
Organic Compounds ◽  
Chemical Properties ◽  
Group Contribution ◽  
Physico Chemical ◽  
Group Contribution Methods

Tool for group contribution methods – computational fragmentation

2010 ◽  
Vol 75 (4) ◽  
pp. 393-404 ◽  
Author(s):  
Zdeňka Kolská ◽  
Pavel Petrus
Keyword(s):  
New Record ◽  
Chemical Properties ◽  
Group Contribution ◽  
Halogenated Hydrocarbons ◽  
Group Contribution Method ◽  
Chemical Structures ◽  
Computational Program ◽  
Physico Chemical ◽  
Group Contribution Methods

Group contribution methods are presently one of the universal and the most frequently used approach to estimate many physico-chemical properties of compounds. One of the important steps in development of group contribution method is a correct division of chemical structures of compounds into defined structural fragments. Computational program dividing automatically chemical structures of compounds (hydrocarbons and halogenated hydrocarbons) into structural fragments are now presented. For description of chemical structures of compounds and structural fragments we used SMILES format. New database of fragments and new record of fragments were created.

Correlations between Molecular Descriptors from Various Volatile Organic Compounds and Photocatalytic Oxidation Kinetic Constants

2013 ◽  
Vol 11 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Cécile Raillard ◽  
Valérie Héquet ◽  
Bifen Gao ◽  
Heyok Choi ◽  
Dionysios D. Dionysiou ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
Molecular Descriptors ◽  
Equilibrium Constants ◽  
Oxidation Kinetic ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Degradation Rates ◽  
Volatile Organic

Abstract The photocatalytic oxidation of seven typical indoor volatile organic compounds (VOCs) is experimentally investigated using novel nanocrystalline TiO2 dip-coated catalysts. Not only the role of hydrophilicity of the reactants but also other physico-chemical properties and molecular descriptors are studied and related to kinetic and equilibrium constants. The main objective of this work consists in establishing simple relationships that will be useful to deepen the understanding of gas-phase heterogeneous photocatalytic mechanisms and for the prediction of degradation rates of these VOCs using an indoor air treatment process.

Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and organic oxidation level

2021 ◽  
Author(s):  
shuang han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Hygroscopic Properties ◽  
Physico Chemical ◽  
Model Predictions ◽  
Hygroscopic Behavior ◽  
Molecular Compounds

<p>Hygroscopic properties of 23 organic compounds with different physico-chemical properties including carboxylic acids, amino acids, sugars and sugar alcohols were measured using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We converted our experimental GF data of organics at 90% RH to κ to facilitate the comparison and we find that organic compounds with different molecular functionality present quite different hygroscopicity. Compounds with extra functional groups usually show higher hygroscopicity compared to their parental molecular compounds. Moreover, some compounds share the same molecular structure or functionality but vary differently in hygroscopicity. In general, the hygroscopicity of organics increase with functional groups in the following order: (-CH3/-NH2) < (-OH) < (-COOH/C=C/C=O). For highly soluble organics, the hygroscopicity decreases with molecular weight; while for slightly soluble organics which are not fully dissolved in aerosol droplets, their hygroscopicity can be divided into two categories. One is non-hygroscopic compounds, which may not fully deliquesce in the aerosol droplets. The other is moderate hygroscopic compounds, of which the hygroscopicity is mainly limited by their water solubility. Moreover, the hygroscopicity of organic compounds generally increased linearly with O:C ratios, although some of them have the same O:C ratio of but with different hygroscopicity. The experimental determined hygroscopicity are also compared with model predictions using the Extended Aerosol Inorganics Model (E-AIM) and the UManSysProp at 10-90% RH. Both models poorly represent the hygroscopic behavior of some organics, which may due to that the phase transition and intermolecular interactions are not considered in the simulations.</p>

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