Semi-empirical topological index to predict properties of halogenated aliphatic compounds

Autor: Érica Silva Souza, Berenice da Silva Junkes, Rosendo A. Yunes, Anna Celia Silva Arruda, Vilma Edite Fonseca Heinzen
Rok vydání: 2008
Předmět:
Zdroj: Journal of Chemometrics. 22:186-194
ISSN: 1099-128X
0886-9383
Popis: This study was carried out to show the predictive capacity of the semi-empirical topological index (/ ET ) in estimating some important physical properties; melting point, Mp (°C), boiling point, Bp (°C), and experimental log p of halogenated aliphatic hydrocarbons. The retention index (RI) values of 141 compounds were used in the building of this specific model of the /ET. The simple linear regression between RI Exp and the / ET exhibits high quality with a coefficient of determination of r 2 = 0.9995, standard deviation of SD =8 and leave-one-out cross-validation correlation coefficient of r 2 cv = 0.999. The best correlations between experimental melting, Mp (°C), and boiling Bp (°C) points, and / ET were achieved through quadratic polynomial equations. The correlation of Bp (°C) with / ET for 86 compounds showed excellent results: r 2 =0.9971, SD=4.2, r 2 cv = 0.997. From this equation the values of 24 compounds not included in the model were calculated (r 2 = 0.9931; SD 7.6). The correlation between Mp (°C) and / ET for 43 compounds was very good (r 2 =0.9865; SD=6.1; r 2 cv =0.985), and experimental values of eight compounds not included in the initial model also showed good correlation with calculated values (r 2 = 0.9903; SD = 4.1). Finally, for 19 compounds the correlation between the experimental log p-value and that calculated using the / ET method gave a value of r 2 = 0.9871, while the correlation with the value obtained using the most used Fragment Addition Method was r 2 = 0.9750. These results show the predictive capacity of the / ET for these physical properties.
Databáze: OpenAIRE
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