In this paper,the dissolution and dissociation enthalpies of benzoic acid in ethanol water and isopropanol H 2O mixtures have been determined by two kinds of microcalorimeters respectively.Combined with the correspond...In this paper,the dissolution and dissociation enthalpies of benzoic acid in ethanol water and isopropanol H 2O mixtures have been determined by two kinds of microcalorimeters respectively.Combined with the corresponding Gibbs function changes existing in the literature,the dissolution and dissociation entropies have been calculated.Great efforts have been made to interpret the characteristic variations of the transfer enthalpies and entropies according to the skin phase model for solute solvent interactions and the structure alteration of the mixed solvents.展开更多
Trifluoromethylation reactions are important transformations in the research and development of drugs, agrochemicals and functional materials. An oxidation/reduction process of trifluoromethyl-containing compounds is ...Trifluoromethylation reactions are important transformations in the research and development of drugs, agrochemicals and functional materials. An oxidation/reduction process of trifluoromethyl-containing compounds is thought to be involved in many recently tested catalytic trifluoromethylation reactions. To provide helpful physical chemical data for mechanistic studies on trifluoromethylation reactions, the redox potentials of a variety of trifluoromethyl-containing compounds and trifluoromethylated radicals were studied by quantum-chemical methods. First, ωB97X-D was found to be a reliable method in predicting the ionization potentials, electron affinities, bond dissociation enthalpies and redox potentials of trifluoromethyl- containing compounds. One-electron absolute redox potentials of 79 trifluoromethyl substrates and 107 trifluoromethylated radicals in acetonitrile were then calculated with this method. The theoretical results were found to be helpful for interpreting experimental observations such as the relative reaction efficiency of different trifluoromethylation reagents. Finally, the bond dissociation free energies(BDFE) of various compounds were found to have a good linear relationship with the related bond dissociation enthalpies(BDE). Based on this observation, a convenient method was proposed to predict one-electron redox potentials of neutral molecules.展开更多
文摘In this paper,the dissolution and dissociation enthalpies of benzoic acid in ethanol water and isopropanol H 2O mixtures have been determined by two kinds of microcalorimeters respectively.Combined with the corresponding Gibbs function changes existing in the literature,the dissolution and dissociation entropies have been calculated.Great efforts have been made to interpret the characteristic variations of the transfer enthalpies and entropies according to the skin phase model for solute solvent interactions and the structure alteration of the mixed solvents.
基金supported by the National Natural Science Foundation of China (21203166, 21073164)Natural Science Foundation of Zhejiang Province, China (Y4100620, LY12B04003)Student Innovation Foundation of Zhejiang Province, China (2012R408007)~~
基金supported by the National Natural Science Foundation of China(21325208,21172209,21361140372,21202006)Specialized Research Fund for the Doctoral Program(20123402110051)+5 种基金Fundamental Research Funds for the Central Universities(WK2060190025)Chinese Academy of Sciences(KJCX2-EW-J02)Fok Ying Tung Education FoundationAnhui Provincial Natural Science Foundation(1308085QB38)China Grid project funded by Ministry of Education of Chinathe supercomputer center of Shanghai and University of Science and Technology of China
文摘Trifluoromethylation reactions are important transformations in the research and development of drugs, agrochemicals and functional materials. An oxidation/reduction process of trifluoromethyl-containing compounds is thought to be involved in many recently tested catalytic trifluoromethylation reactions. To provide helpful physical chemical data for mechanistic studies on trifluoromethylation reactions, the redox potentials of a variety of trifluoromethyl-containing compounds and trifluoromethylated radicals were studied by quantum-chemical methods. First, ωB97X-D was found to be a reliable method in predicting the ionization potentials, electron affinities, bond dissociation enthalpies and redox potentials of trifluoromethyl- containing compounds. One-electron absolute redox potentials of 79 trifluoromethyl substrates and 107 trifluoromethylated radicals in acetonitrile were then calculated with this method. The theoretical results were found to be helpful for interpreting experimental observations such as the relative reaction efficiency of different trifluoromethylation reagents. Finally, the bond dissociation free energies(BDFE) of various compounds were found to have a good linear relationship with the related bond dissociation enthalpies(BDE). Based on this observation, a convenient method was proposed to predict one-electron redox potentials of neutral molecules.
