A Group Contribution Model for Determining the Vaporization Enthalpy of Organic Compounds at the Standard Reference Temperature of 298 K

Article on a group contribution model for determining the vaporization enthalpy of organic compounds at the standard reference temperature of 298 K

A group contribution model for determining the sublimation enthalpy of organic compounds at the standard reference temperature of 298 K

Article discussing a group contribution model for determining the sublimation enthalpy of organic compounds at the standard reference temperature of 298 K

A group contribution model for determining the vaporization enthalpy of organic compounds at the standard reference temperature of 298K

Article on a group contribution model for determining the vaporization enthalpy of organic compounds at the standard reference temperature of 298 K

Determination of Diffusion Coefficient of Organic Compounds in Water Using a Simple Molecular-Based Method

In this study, a new simple three-parameter equation is presented for calculation/prediction of the diffusion coefficient of nonelectrolyte organic compounds in water at infinite dilution. The model variables include three molecular-based descriptors. The model is developed using the genetic function approximation (GFA) method. The GFA is applied to select the parameters of the model from more than 3000 molecular-based parameters. To propose a comprehensive and predictive model, 4728 pure chemical compounds are investigated. Furthermore, several statistical methods are implemented to evaluate the predictive power of the model. The root-mean-square of error and the average relative deviation of the model are approximately equal to 3.13 × 10^–6 cm²·s^–1 and 3.6%

Quantitative Structure−Property Relationship for Prediction of the Lower Flammability Limit of Pure Compounds

A quantitative structure−property relationship (QSPR) study was performed to develop a model for prediction of the lower flammability limit (LFL) of pure compounds. The obtained model is a four-parameter multilinear equation. These four parameters are calculated from the chemical structure of every molecule. The average absolute error, squared correlation coefficient, and root mean squares of error of the obtained model over all 1056 pure compounds used to develop the model are 7.68%, 0.9698, and 0.084, respectively

Chemical Structure-Based Model for Estimation of the Upper Flammability Limit of Pure Compounds

In the present work, a new molecular-based model is presented for estimation of the upper flammability limit (UFL) of pure compounds. The parameters of the model are the number of occurrences of a new collection of 113 functional groups. On the basis of these 113 functional groups, a feed-forward neural network is presented to estimate the UFL of pure compounds. The squared correlation coefficient, absolute percent error, standard deviation, and root-mean-square error of the model over the 867 pure compounds used for the development of the model are 0.9469, 7.07%, 0.883, 0.882, respectively. Therefore, the model is accurate and can be used to predict the UFL for a wide range of pure compounds

Correction: Vatani, A., et al. Prediction of Standard Enthalpy of Formation by a QSPR Model. Int. J. Mol. Sci. 2007, 8, 407-432.

We found an error in our paper published in the Int. J. Mol. Sci. recently [1]: on page 409, the Equation (2) should be printed as: [...

Development of a group contribution method for determination of viscosity of ionic liquids at atmospheric pressure

International audienceIn this study, a wide literature survey has been carried out to collect an extensive set of liquid viscosity data for ionic liquids (ILs). A data set consisting of 1672 viscosity values and comprising 443 ILs was collated from 204 different literature sources. Using this data set, a reliable group contribution method has been developed. The method employs a total of 46 sub-structures in addition to the temperature to predict the viscosity of ILs. In order to differentiate the effects of the anion and cation on the viscosity of ILs, 24 sub-structures related to the chemical structure of anions, and 22 sub-structures related to the chemical structure of cations were implemented. The proposed model produces a low average relative deviation (AARD) of less than 6.4% taking into consideration all 1672 experimental data values