This work presents a thermodynamic method for treating nonequilibrium solvation. By imposing an extra electric field onto the nonequilibrium solvation system, a virtual constrained equilibrium state is prepared. In th...This work presents a thermodynamic method for treating nonequilibrium solvation. By imposing an extra electric field onto the nonequilibrium solvation system, a virtual constrained equilibrium state is prepared. In this way, the free energy difference between the real nonequilibrium state and the con-strained equilibrium one is simply the potential energy of the nonequilibrium polarization in the extra electronic field, according to thermodynamics. Further, new expressions of nonequilibrium solvation energy and solvent reorganization energy have been formulated. Analysis shows that the present formulations will give a value of reorganization energy about one half of the traditional Marcus theory in polar solvents, thus the explanation on why the traditional theory tends to overestimate this quantity has been found out. For the purpose of numerical determination of solvent reorganization energy, we have modified Gamess program on the basis of dielectric polarizable continuum model. Applying the procedure to the well-investigated intramolecular electron transfer in biphenyl-androstane-naphthyl and biphenyl-androstane-phenanthryl systems, the numerical results of solvent reorganization energy have been found to be in good agreement with the experimental fittings.展开更多
As a successive work of our previous paper, 1 the electron transfer matrix element (V rp) in the oxidation of the simplified model molecule of α-amino carbon-centered radical by O 2 has been investigated wi...As a successive work of our previous paper, 1 the electron transfer matrix element (V rp) in the oxidation of the simplified model molecule of α-amino carbon-centered radical by O 2 has been investigated with ab initio calculation at the level of UHF/6-31++G**. Based on the optimized geometries of the reactant and the ion-pair complex obtained previously, the reaction heat and the inner reorganization energy have been obtained by constructing the potential energy curves of reactant and product states considering the solvent effect with the conductor-like screening model (COSMO). The solvent reorganization energy has been estimated using Lippert-Mataga relationship. The calculated results show that the value of V rp is several times larger than that of RT, which means that the model reaction is an adiabatic one. Theoretical investigation indicates that the solvent effect on the direct electron transfer (ET) process of oxidation of α-amino carbon-centered radical by oxygen is remarkable.展开更多
On the basis of the electromagnetic field theory and the spherical cavity approximation, the expressions ofGibbs free energies under equilibrium and non-equilibrium solvation conditions are obtained by solving the ele...On the basis of the electromagnetic field theory and the spherical cavity approximation, the expressions ofGibbs free energies under equilibrium and non-equilibrium solvation conditions are obtained by solving the electrostatic potential equations with boundary conditions. The surface charges produced by the orientational polarization of equi-librium solvation are taken fixed in the case of non-equilibrium situation, for the slow-response of the orientational polarization to electron transfer of the solvent molecules. Anew expression of solvent reorganization energy has beenobtained and this method is applied to the electron transfer systems, NO+/NO, NO2+/NO2, and NO2+/NO. The solvent reorganization energies have been evaluated.展开更多
Faults existing in the current theories of non- equilibrium solvation have been clarified in this report. Based on a novel expression of solvation free energy for nonequilibrium, generalized formulations of solvent re...Faults existing in the current theories of non- equilibrium solvation have been clarified in this report. Based on a novel expression of solvation free energy for nonequilibrium, generalized formulations of solvent reor- ganization energy for electron transfer and of solvation shift for spectrum have been established. Furthermore, a new form of solvent reorganization energy for electron transfer in two-sphere case, which greatly differs from the one by Mar- cus, has been deduced. A single-sphere model for solvation shift of spectrum has been put forward both by deducing the generalized formulations and by showing the correct forms of self-energy of reaction field. It has been concluded that the current theories overestimate the solvent reorganization energy and the solvation shift by a factor of about 2. By apply- ing the models established, the discrepancies between the theory and experiments before have been perfectly explained.展开更多
In this work, the authors give detailed deductions and develop the single-sphere model of solvent reorganization energy in electron transfer with point dipole approximation. At the level of DFT/6- 31++G**, the electro...In this work, the authors give detailed deductions and develop the single-sphere model of solvent reorganization energy in electron transfer with point dipole approximation. At the level of DFT/6- 31++G**, the electron transfer between 7,7,8,8-tet-racyanoquinodimethane and its anion has been investigated. Using the novel single-sphere model, the authors evaluate the solvent reorganization energy of this system, and the computational result proves rational in comparison with the experimental estimations.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20533070 and 20625311)
文摘This work presents a thermodynamic method for treating nonequilibrium solvation. By imposing an extra electric field onto the nonequilibrium solvation system, a virtual constrained equilibrium state is prepared. In this way, the free energy difference between the real nonequilibrium state and the con-strained equilibrium one is simply the potential energy of the nonequilibrium polarization in the extra electronic field, according to thermodynamics. Further, new expressions of nonequilibrium solvation energy and solvent reorganization energy have been formulated. Analysis shows that the present formulations will give a value of reorganization energy about one half of the traditional Marcus theory in polar solvents, thus the explanation on why the traditional theory tends to overestimate this quantity has been found out. For the purpose of numerical determination of solvent reorganization energy, we have modified Gamess program on the basis of dielectric polarizable continuum model. Applying the procedure to the well-investigated intramolecular electron transfer in biphenyl-androstane-naphthyl and biphenyl-androstane-phenanthryl systems, the numerical results of solvent reorganization energy have been found to be in good agreement with the experimental fittings.
文摘As a successive work of our previous paper, 1 the electron transfer matrix element (V rp) in the oxidation of the simplified model molecule of α-amino carbon-centered radical by O 2 has been investigated with ab initio calculation at the level of UHF/6-31++G**. Based on the optimized geometries of the reactant and the ion-pair complex obtained previously, the reaction heat and the inner reorganization energy have been obtained by constructing the potential energy curves of reactant and product states considering the solvent effect with the conductor-like screening model (COSMO). The solvent reorganization energy has been estimated using Lippert-Mataga relationship. The calculated results show that the value of V rp is several times larger than that of RT, which means that the model reaction is an adiabatic one. Theoretical investigation indicates that the solvent effect on the direct electron transfer (ET) process of oxidation of α-amino carbon-centered radical by oxygen is remarkable.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39970183).
文摘On the basis of the electromagnetic field theory and the spherical cavity approximation, the expressions ofGibbs free energies under equilibrium and non-equilibrium solvation conditions are obtained by solving the electrostatic potential equations with boundary conditions. The surface charges produced by the orientational polarization of equi-librium solvation are taken fixed in the case of non-equilibrium situation, for the slow-response of the orientational polarization to electron transfer of the solvent molecules. Anew expression of solvent reorganization energy has beenobtained and this method is applied to the electron transfer systems, NO+/NO, NO2+/NO2, and NO2+/NO. The solvent reorganization energies have been evaluated.
基金supported by the National Natural Science Foundation of Chinathe Trans-Century Training Program Foundation for the Talents by the Ministry of Education of China
文摘Faults existing in the current theories of non- equilibrium solvation have been clarified in this report. Based on a novel expression of solvation free energy for nonequilibrium, generalized formulations of solvent reor- ganization energy for electron transfer and of solvation shift for spectrum have been established. Furthermore, a new form of solvent reorganization energy for electron transfer in two-sphere case, which greatly differs from the one by Mar- cus, has been deduced. A single-sphere model for solvation shift of spectrum has been put forward both by deducing the generalized formulations and by showing the correct forms of self-energy of reaction field. It has been concluded that the current theories overestimate the solvent reorganization energy and the solvation shift by a factor of about 2. By apply- ing the models established, the discrepancies between the theory and experiments before have been perfectly explained.
基金supported by the National Natural Science Foundation of China(Grant Nos.20473054 and 20572073).
文摘In this work, the authors give detailed deductions and develop the single-sphere model of solvent reorganization energy in electron transfer with point dipole approximation. At the level of DFT/6- 31++G**, the electron transfer between 7,7,8,8-tet-racyanoquinodimethane and its anion has been investigated. Using the novel single-sphere model, the authors evaluate the solvent reorganization energy of this system, and the computational result proves rational in comparison with the experimental estimations.
