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Over the years, RuIV(bpy)2(py)(O)2+([RuIVO]2+) has garnered considerable interest owing to its extensive use as a polypyridine mono-oxygen complex. However, as the active-site Ru=O bond changes during the oxidation process, [RuIVO]2+ can be used to simulate the reactions of various high-priced metallic oxides. In order to elucidate the hydrogen element transfer process between the Ruthenium-oxo-polypyridyl complex and organic hydride donor, the current study reports on the synthesis of [RuIVO]2+, a polypyridine mono-oxygen complex, in addition to 1H and 3H (organic hydride compounds) and 1H derivative: 2. Through 1H-NMR analysis and thermodynamics- and kinetics-based assessments, we collected data on [RuIVO]2+ and two organic hydride donors and their corresponding intermediates and established a thermodynamic platform. It was confirmed that a one-step hydride transfer reaction between [RuIVO]2+ and these organic hydride donors occurs, and here, the advantages and nature of the new mechanism approach are revealed. Accordingly, these findings can considerably contribute to the better application of the compound in theoretical research and organic synthesis. [ABSTRACT FROM AUTHOR]

In this work, we compared the hydride-donating ability of five-membered benzoheterocyclic compounds (FMB) and six-membered benzoheterocyclic compounds (SMB), isomers of DMBI and DMIZ and of DMPZ and DMPX, using detailed thermodynamic driving forces [ΔGo (XH)], kinetic intrinsic barriers (ΔG≠XH/X), and thermo-kinetic parameters [ΔG≠° (XH)]. For DMBI and DMIZ, the values of ΔGo (XH), ΔG≠XH/X, and ΔG≠° (XH) are 49.2 and 53.7 kcal/mol, 35.88 and 42.04 kcal/mol, and 42.54 and 47.87 kcal/mol, respectively. For DMPZ and DMPX, the values of ΔGo (XH), ΔG≠XH/X, and ΔG≠° (XH) are 73.2 and 79.5 kcal/mol, 35.34 and 25.02 kcal/mol, and 54.27 and 52.26 kcal/mol, respectively. It is easy to see that the FMB isomers are thermodynamically dominant and that the SMB isomers are kinetically dominant. Moreover, according to the analysis of ΔG≠° (XH), compared to the SMB isomers, the FMB isomers have a stronger hydride-donating ability in actual chemical reactions. [ABSTRACT FROM AUTHOR]

In this paper, detailed comparisons of the driving force in thermodynamics and intrinsic force in the kinetics of 1,2-dihydropyridine and 1,4-dihydropyridine isomers of PNAH, HEH, and PYH in hydride transfer reactions are made. For 1,2-PNAH and 1,4-PNAH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 60.50 and 61.90 kcal/mol, 27.92 and 26.34 kcal/mol, and 44.21 and 44.12 kcal/mol, respectively. For 1,2-HEH and 1,4-HEH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 63.40 and 65.00 kcal/mol, 31.68 and 34.96 kcal/mol, and 47.54 and 49.98 kcal/mol, respectively. For 1,2-PYH and 1,4-PYH, the order of thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic parameters are 69.90 and 72.60 kcal/mol, 33.06 and 25.74 kcal/mol, and 51.48 and 49.17 kcal/mol, respectively. It is not difficult to find that thermodynamically favorable structures are not necessarily kinetically favorable. In addition, according to the analysis of thermo-kinetic parameters, 1,4-PNAH, 1,2-HEH, and 1,4-PYH have a strong hydride-donating ability in actual chemical reactions. [ABSTRACT FROM AUTHOR]

The object of this fundamental research would reveal the actual antioxidant ability of the antioxidants using thermo‐kinetic parameter ΔG≠o which was proposed according to Zhu kinetic model. Kinetic experiments on the reactions between Vitamin C, Vitamin E, and NADH analog (BNAH) with DPPH• and tBu3PhO• radicals were made to measure the reaction rate constants in acetonitrile at 298 K. The ΔG≠o (XH) values of Vitamin C, Vitamin E, and BNAH in acetonitrile at 298 K were estimated, and the bond dissociation free energies ΔGo (XH) and kinetic intrinsic barriers ΔG≠XH/X of these three antioxidants to release hydrogen atoms were also compared. Only the data of thermo‐kinetic parameters ΔG≠o (XH) are consistent with the true oxidation sequence. The order of the actual antioxidant activity of these three antioxidants is Vitamin C > Vitamin E > NADH. All our preliminary results throw light on the nature of actual antioxidant ability of antioxidants, which not only depend on thermodynamic driving force, but also depend on the dynamic resistance. Therefore, thermo‐kinetic parameter ΔG≠o is the perfect parameter which can be used as measurement criteria of the actual antioxidant ability of antioxidants. [ABSTRACT FROM AUTHOR]

In this work, the thermodynamic and kinetic forces of three NADH analogues as BNAH, HEH2, and AcrH2, to release hydride ion or hydrogen atom in acetonitrile in chemical reactions were discussed and researched, which was important for chemists to understand the real capacity of hydride‐donating, hydrogen‐atom‐donating of these three compounds. By comparing the bond dissociation free energy [ΔGo(XL)], self‐exchange reaction activation energy [ΔG≠XL/X], and thermo‐kinetic parameter [ΔG≠°(XL)] of these three compounds to release hydride ion or hydrogen atom, it's easy to find that reactions that thermodynamically favorable were not necessarily kinetically favorable. Therefore, it's unreasonable to judge the hydride‐donating ability or hydrogen‐atom‐donating ability of a compound only by its thermodynamic parameter or kinetic parameter. In addition, with these thermodynamic and kinetic parameters, we are better able to select suitable compound as model of NADH which based on different requirement in reactions. [ABSTRACT FROM AUTHOR]

In this work, 1,5-dihydro-3,4-dihydroxy-2-pyrrolone derivatives (XH2) and their anions (XH−) were designed and synthesized as the synthetic vitamin C analogs. The thermodynamic driving forces of the 8 possible elementary steps for XH2 to release 2 hydrogen atoms to become X in acetonitrile were determined using experimental methods. The mechanisms and the possible reaction intermediates of XH2 and XH− reacted by DPPH • in acetonitrile were examined or predicted using the determined thermodynamic analysis combining the kinetics. [ABSTRACT FROM AUTHOR]