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Orientador(es)
Resumo(s)
Solution enthalpies of 1,4-dioxane have been obtained in 15 protic and aprotic solvents at 298.15 K. Breaking the overall process through the use of Solomonov's methodology the cavity term was calculated and interaction enthalpies (Delta H-int) were determined. Main factors involved in the interaction enthalpy have been identified and quantified using a QSPR approach based on the TAKA model equation. The relevant descriptors were found to be pi* and beta, which showed, respectively, exothermic and endothermic contributions.
The magnitude of pi* coefficient points toward non-specific solute-solvent interactions playing a major role in the solution process. The positive value of the beta coefficient reflects the endothermic character of the solvents' hydrogen bond acceptor (HBA) basicity contribution, indicating that solvent molecules engaged in hydrogen bonding preferentially interact with each other rather than with 1,4-dioxane. (C) 2013 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
Solution enthalpy Interaction enthalpy Cavity term Kamlet-taft parameters QSPR Carbon-atom replacement Acetone molecule can Base-acid properties Cyclic ethers Thermochemical behavior Preferential solvation Macrocycle interation Binary-mixtures Crown-ethers
Contexto Educativo
Citação
NUNES, Nelson; REIS, Marina; MOREIRA, Luís; LEITÃO, Ruben Elvas; MARTINS, Filomena - GONZALEZ, R. Felipe; JOAQUIM, F. R. - Solution enthalpies of 1,4-dioxane: study of solvent effects through quantitative structure-property relationships. Thermochimica Acta. ISSN 0040-6031. Vol. 574, (2013), p. 85-87.