Estimation of Standard Reduction Potentials of Halogen Atoms and Alkyl Halides

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• 作者：Abdirisak A. Isse ; Ching Yeh Lin ; Michelle L. Coote ; Armando Gennaro
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：February 3, 2011
• 年：2011
• 卷：115
• 期：4
• 页码：678-684
• 全文大小：175K
• 年卷期：v.115,no.4(February 3, 2011)
• ISSN：1520-5207

文摘

Standard reduction potentials, SRPs, of the halogen atoms have been calculated in water on the basis of an appropriate thermochemical cycle. Using the best up-to-date thermodynamic data available in the literature, we have calculated EX鈥?/sup>/X鈭?/sup>o̵ values of 3.66, 2.59, 2.04, and 1.37 V vs SHE for F鈥?/sup>, Cl鈥?/sup>, Br鈥?/sup>, and I鈥?/sup>, respectively. Additionally, we have computed the SRPs of Cl鈥?/sup>, Br鈥?/sup>, and I鈥?/sup> in acetonitrile (CH3CN) and dimethylformamide (DMF) by correcting the values obtained in water for the free energies of transfer of X鈥?/sup> and X鈭?/sup> from water to the nonaqueous solvent S and the intersolvent potential between water and S. From the values of EX鈥?/sup>/X鈭?/sup>o̵ in CH3CN and DMF, the SRPs of a series of alkyl halides of relevance to atom transfer radical polymerization and other important processes such as pollution abatement have been calculated in these two solvents. This has been done with the aid of a thermochemical cycle involving the gas-phase homolytic dissociation of the C鈭扻 bond, solvation of RX, R鈥?/sup>, and X鈥?/sup>, and reduction of X鈥?/sup> to X鈭?/sup> in solution.