Theoretical Calculations for the Acidity of Cyanopolyynes HC2n+1N (n = 0–5) in Gas and Aqueous Phases Using Ab initio Methods

Hassan H. Abdallah

doi:10.14500/aro.10484

Hassan H. Abdallah Department of Chemistry, College of Education, Salahaddin University-Erbil, Kurdistan Region http://orcid.org/0000-0002-9198-0475

Keywords: Ab initio, Acidity, Cyanopolyynes, Density functional theory, Møller–Plesset perturbation

Abstract

Cyanopolyynes have been found in the interstellar medium, cold dust cloud Taurus Molecular Cloud-1, and the Titan’s atmosphere. Theoretical calculations are carried out to predict gas and aqueous phase acidities of a series of cyanopolyynes acids. Two levels of theory were used in this study, with the combination of density functional theory, and Møller–Plesset perturbation (MP2) theory, MP2 methods with two types of basis set, namely, Pople’s 6–311++g (d, p) basis set and Dunning’s aug-cc-pVTZ basis set. The calculations of these molecules reveal that pKa values varying from 12.25 to 17.25 and indicate that the acidity of these molecules in aqueous phase increases whereas the acidity in gas phase decreases with an increasing chain length of these acids.

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Author Biography

Hassan H. Abdallah, Department of Chemistry, College of Education, Salahaddin University-Erbil, Kurdistan Region

Hassan H. Abdallah is an Assistant Professor at Department of Chemistry, College of Education, Salahaddin University-Erbil.He has a Ph.D. degree in Quantum Chemistry. His research fields are, computational chemistry and drug design.

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