Calculation of Hydrogen Bonding Enthalpy Using the Two-Parameter Abraham Equation
In this work, an approach to the calculation of hydrogen bonding enthalpies is proposed. It employs the correlation proposed by M.H. Abraham, establishing the connection between the equilibrium constant (<i>K</i><sub>HB</sub>) and acidity (<inline-formula><math xmlns...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-09-01
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| Series: | Liquids |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2673-8015/4/3/34 |
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| Summary: | In this work, an approach to the calculation of hydrogen bonding enthalpies is proposed. It employs the correlation proposed by M.H. Abraham, establishing the connection between the equilibrium constant (<i>K</i><sub>HB</sub>) and acidity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>α</mi><mn>2</mn><mi mathvariant="normal">H</mi></msubsup></mrow></semantics></math></inline-formula>) and basicity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>β</mi><mn>2</mn><mi mathvariant="normal">H</mi></msubsup></mrow></semantics></math></inline-formula>) parameters: log <i>K</i><sub>HB</sub> = 7.354 · <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>α</mi><mn>2</mn><mi>H</mi></msubsup></mrow></semantics></math></inline-formula> · <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>β</mi><mn>2</mn><mi>H</mi></msubsup></mrow></semantics></math></inline-formula> − 1.099. Hydrogen bonding enthalpy (Δ<sub>HB</sub><i>H</i>) is found using the compensation relationship with Gibbs energy (Δ<sub>HB</sub><i>G</i>): Δ<sub>HB</sub><i>G</i> = 0.66 · Δ<sub>HB</sub><i>H</i> + 2.5 kJ·mol<sup>−1</sup>. This relationship enables the calculation of the enthalpy, Gibbs energy and entropy of hydrogen bonding. The validity of this approach was tested against 122 experimental hydrogen bonding enthalpies values available from the literature. The root mean square deviation and average deviation equaled 1.6 kJ·mol<sup>−1</sup> and 0.5 kJ·mol<sup>−1</sup>, respectively. |
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| ISSN: | 2673-8015 |