The selected-state probabilities of collinear ion-pair formation process Na+I2→Na++I2-on Aten-Laming-Los two-State potential energy surface have been calculated by using LCAC-SW method. The results show that reaction...The selected-state probabilities of collinear ion-pair formation process Na+I2→Na++I2-on Aten-Laming-Los two-State potential energy surface have been calculated by using LCAC-SW method. The results show that reaction probabilities are oscillatory with collision energy; the threshold energy of this ioniZation reaction is 2.8 ev, which is in modest agreement with experimental result.展开更多
In this letter the study of Li-doped zinc oxide by electron paramagnetic resonance method is described.A signal observed at g_=2.013,g_=1.955 on the degassed sample at 923K was designated to F_s^+ centers(surface oxyg...In this letter the study of Li-doped zinc oxide by electron paramagnetic resonance method is described.A signal observed at g_=2.013,g_=1.955 on the degassed sample at 923K was designated to F_s^+ centers(surface oxygen ion vacancies with a single trapped electron).When the sample was quenched from 1003K into liquid oxygen at 77K under 24 KPa O_2,[Li^+O^-] ion pairs valued at g_=2.026 and g=2.003 with superhyperfine constant a=2.0G,which resulted from ~7Li nucleus,formed at Li^+-substitutional site in ZnO lattice.A probable mechanism of [Li^+O^-]ion pair formation was proposed.展开更多
For the Li + I2 →Li+ + I2- system, theoretical study has been performed on the QCISD(T) level by using the ab initio method. The collision complex in ion-pair formation process was found and optimized. These results ...For the Li + I2 →Li+ + I2- system, theoretical study has been performed on the QCISD(T) level by using the ab initio method. The collision complex in ion-pair formation process was found and optimized. These results show that the crossed molecule beam (CMB) experimental phenomenon is verified and the detailed geometry is given for the first time. A mechanism for ion-pair formation was proposed in detail. The position where the collision complex occurs affects the reaction path. Specifically, the process has threshold when the collision complex appeared before the crossing point between the covalent and ionic state potential energy surfaces. On the contrary, the process has no threshold after the crossing point. Theoretically, the title system belongs to the former case.展开更多
The laser ablation-molecular beam（LA-MB） method is useful for studying the reactions of metal ions with molecular clusters. Reactions of magnesium plasma with methanol clusters were studied by using this method. A s...The laser ablation-molecular beam（LA-MB） method is useful for studying the reactions of metal ions with molecular clusters. Reactions of magnesium plasma with methanol clusters were studied by using this method. A specially designed reaction cell was used as a fast flow reactor operated under thermal conditions, and the reaction products were measured with a time-of-flight（TOF） mass spectrometer. Surprisingly, several series of cluster ions with complex sizes and intensity distributions were obtained when the laser ablating was applied to different parts of the molecular beam. In the front part of the molecular beam, strong Mg^＋ （CH3OH）n（ n = 0-5） and weak H^＋ （CH3OH）n（ n = 0-5 ） cluster ions were observed with relatively small cluster sizes ; in the middle part of the molecular beam, the main cluster ions were H^＋ （ CH3OH）n （ n = 6-17 ） and H^＋（ H2O） 2 （ CH3OH）n（ n = 6-17 ） with a relatively large cluster size and a weak intensity; in the back part of the molecular beam, two new series of cluster ions, MgO^＋ （ H2O） （ CH3 OH）n（ n = 6-10 ） and MgOCH3^＋ （ CH3OH）n（ n = 6-10）, were obtained and accompanied by weak H^＋（CH3OH）n（n = 4-7） and H^＋（ H2O）2 （CH3OH）n（ n = 3-6）. The formation mechanisms and speed characteristics of the cluster ions are discussed in this article.展开更多
Ionic strength conditions in distribution experiments with single ions are very important for evaluating their distribution properties. Distribution experiments of picrates (MPic) with M = Ag(I) and Li(I)-Cs(I) into o...Ionic strength conditions in distribution experiments with single ions are very important for evaluating their distribution properties. Distribution experiments of picrates (MPic) with M = Ag(I) and Li(I)-Cs(I) into o-dichlorobenzene (oDCBz) were performed at 298 K by changing volume ratios (Vorg/V) between water and oDCBz phases, where “org” shows an organic phase. Simultaneously, an analytic equation with the Vorg/V variation was derived in order to analyze such distribution systems. Additionally, the AgPic distribution into nitrobenzene (NB), dichloromethane, and 1,2-dichloroethene (DCE) and the NaB(C6H5) 4 (=NaBPh4) one into NB and DCE were studied at 298 K under the conditions of various Vorg/V values. So, extraction constants (Kex) for MPic into the org phases, their ion-pair formation constants (KMA,org) for MA = MPic in the org ones, and standard distribution constants () for the M(I) transfers between the water and org bulk phases with M = Ag and Li-Cs were determined at the distribution equilibrium potential (dep) of zero V between the bulk phases and also the Kex (NaA), KNaA,org, and values were done at A-=BPh-4. Here, the symbols Kex, KMA,org, and or were defined as [MA] org/[M+][A-], [MA] org/[M+]org [A-]org, and [M+]org/[M+] or [A-]org/[A-] at dep = 0, respectively. Especially, the ionic strength dependences of Kex and KMPic,org were examined at M = Li(I)-K(I) and org = oDCBz. From above, the conditional distribution constants, KD,BPh4 and KD,Cs, were classified by checking the experimental conditions of the I, Iorg, and dep values.展开更多
This paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equation mR=-dV(R)/dR, an...This paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equation mR=-dV(R)/dR, and has calculated the cross sections of ion-pair formation Cs+O2 -Cs++O2- with the improved nonadiabatic collision model (INCM). A comparison of our results with other theoretical and experimental results has been made.展开更多
For the Na + I2 collision system, theoretical study is performed on the QCISD(T) level by using ab initio method. The ab initio potential energy surfaces are got and on them the long-lived complexes are found and opti...For the Na + I2 collision system, theoretical study is performed on the QCISD(T) level by using ab initio method. The ab initio potential energy surfaces are got and on them the long-lived complexes are found and optimized. These results verify the crossed molecule beam experimental phenomenon and the detailed geometry structures are given for the first time. The role of the complexes in the reaction path is also described in detail.展开更多
CdI2 in water was extracted with 18-crown-6 ether (L) into 10 diluents at 298 K. The following equilibrium constants were determined or evaluated: some extraction constants (Kex/mol-3·dm9 & Kex,ip/mol-2·...CdI2 in water was extracted with 18-crown-6 ether (L) into 10 diluents at 298 K. The following equilibrium constants were determined or evaluated: some extraction constants (Kex/mol-3·dm9 & Kex,ip/mol-2·dm6 for CdLI2, Kex±/mol-2·dm6 for CdLI+ with I-, & Kex2±/mol-1·dm3 for CdL2+ with 2I-), conditional distribution constants (KD,I for I-, KD,CdLI for CdLI+, & KD,CdL for CdL2+) between the two phases, and an ion-pair formation constant (K1,org/mol-1·dm3) for CdLI+ and that (K2,org/mol-1·dm3) for CdLI2 in the organic (org) phases. Using the K1,org and K2,org values, acidities of the complex ions, CdL2+ and CdLA+ (A- = I-, Br-, & Cl-), in the 11 diluents were classified by applying the HSAB rule. Especially, the CdLA+ ions were classified as the soft acids in 9 diluents. Also, molar volumes (Vj/cm3·mol-1) of j = CdLI2 and CdL2+ were determined with the regular-solution-theory plot of logKex,ip vs. logKD,L and its pseudo-plot of logKD,CdL, respectively. Here, KD,L denotes the distribution constant of L between the two phases. So, sizes among CdLA2 and CdL2+ were compared by using the Vj values. Additionally, some distribution equilibrium potentials (dep/V) between the water and org bulk phases were topically calculated from an equation of KD,I with KSD,I, where the symbol KSD,I shows a standard distribution constant of I- at dep = 0 V for a given diluent.展开更多
Aprotic Li-CO_(2)batteries have attracted growing interest due to their high theoretical energy density and its ability to use green house gas CO_(2)for energy storage.However,the poor ability of activating CO_(2)in o...Aprotic Li-CO_(2)batteries have attracted growing interest due to their high theoretical energy density and its ability to use green house gas CO_(2)for energy storage.However,the poor ability of activating CO_(2)in organic electrolyte often leads to the premature termination of CO_(2)reduction reaction(CO_(2)RR)directly.Here in this work,cetyl trimethyl ammonium bromide(CTAB)was introduced into a dimethyl sulfoxide(DMSO)based Li-CO_(2)battery for the first time to enhance the CO_(2)RR.Significantly improved electrochemical performances,including reduced discharge over-potential and increased discharge capacity,can be achieved with the addition of CTAB.Ab initio molecular dynamics(AIMD)simulations show that quaternary ammonium group CTA^(+) can accelerate CO_(2)reduction process by forming more stable contact ion pair(CIP)with CO_(2)^(–),reducing the energy barrier for CO_(2)RR,thus improving the CO_(2)reduction process.In addition,adding CTA^(+) is also favorable for the solution-phase growth of discharge products because of the improved migration ability of stable CTA^(+)-CO_(2)^(–) CIP in the electrolyte,which is beneficial for improving the utilization ratio of cathode.This work could facilitate the development of CO_(2)RR by providing a novel understanding of CO_(2)RR mechanism in organic system.展开更多
An extended LCAC\|SW(Linear Combination of Arrangement Channels\|Scattering Wavefunction) quantum scattering dynamic method combined with \%ab initio\% quantum chemical calculations has been used to study the formatio...An extended LCAC\|SW(Linear Combination of Arrangement Channels\|Scattering Wavefunction) quantum scattering dynamic method combined with \%ab initio\% quantum chemical calculations has been used to study the formation mechanism of the resonance states for ion\|pair formation reaction Na+I\-2 Na\+++I\+-\-2. Resonance energy and width or lifetime for the first resonance peak were calculated. Resonance can be identified to Feshbach resonance and the physical interpretation was given.展开更多
文摘The selected-state probabilities of collinear ion-pair formation process Na+I2→Na++I2-on Aten-Laming-Los two-State potential energy surface have been calculated by using LCAC-SW method. The results show that reaction probabilities are oscillatory with collision energy; the threshold energy of this ioniZation reaction is 2.8 ev, which is in modest agreement with experimental result.
基金Supported by Chinese National Scientific Foundation
文摘In this letter the study of Li-doped zinc oxide by electron paramagnetic resonance method is described.A signal observed at g_=2.013,g_=1.955 on the degassed sample at 923K was designated to F_s^+ centers(surface oxygen ion vacancies with a single trapped electron).When the sample was quenched from 1003K into liquid oxygen at 77K under 24 KPa O_2,[Li^+O^-] ion pairs valued at g_=2.026 and g=2.003 with superhyperfine constant a=2.0G,which resulted from ~7Li nucleus,formed at Li^+-substitutional site in ZnO lattice.A probable mechanism of [Li^+O^-]ion pair formation was proposed.
基金Supported by the grants of the National Natural Science Foundation of China (No. 20173032) and Ph.D. Special Research Foundation of the Chinese Education Department
文摘For the Li + I2 →Li+ + I2- system, theoretical study has been performed on the QCISD(T) level by using the ab initio method. The collision complex in ion-pair formation process was found and optimized. These results show that the crossed molecule beam (CMB) experimental phenomenon is verified and the detailed geometry is given for the first time. A mechanism for ion-pair formation was proposed in detail. The position where the collision complex occurs affects the reaction path. Specifically, the process has threshold when the collision complex appeared before the crossing point between the covalent and ionic state potential energy surfaces. On the contrary, the process has no threshold after the crossing point. Theoretically, the title system belongs to the former case.
基金Supported by the Doctoral Startup Foundation from Qufu Normal University.
文摘The laser ablation-molecular beam（LA-MB） method is useful for studying the reactions of metal ions with molecular clusters. Reactions of magnesium plasma with methanol clusters were studied by using this method. A specially designed reaction cell was used as a fast flow reactor operated under thermal conditions, and the reaction products were measured with a time-of-flight（TOF） mass spectrometer. Surprisingly, several series of cluster ions with complex sizes and intensity distributions were obtained when the laser ablating was applied to different parts of the molecular beam. In the front part of the molecular beam, strong Mg^＋ （CH3OH）n（ n = 0-5） and weak H^＋ （CH3OH）n（ n = 0-5 ） cluster ions were observed with relatively small cluster sizes ; in the middle part of the molecular beam, the main cluster ions were H^＋ （ CH3OH）n （ n = 6-17 ） and H^＋（ H2O） 2 （ CH3OH）n（ n = 6-17 ） with a relatively large cluster size and a weak intensity; in the back part of the molecular beam, two new series of cluster ions, MgO^＋ （ H2O） （ CH3 OH）n（ n = 6-10 ） and MgOCH3^＋ （ CH3OH）n（ n = 6-10）, were obtained and accompanied by weak H^＋（CH3OH）n（n = 4-7） and H^＋（ H2O）2 （CH3OH）n（ n = 3-6）. The formation mechanisms and speed characteristics of the cluster ions are discussed in this article.
文摘Ionic strength conditions in distribution experiments with single ions are very important for evaluating their distribution properties. Distribution experiments of picrates (MPic) with M = Ag(I) and Li(I)-Cs(I) into o-dichlorobenzene (oDCBz) were performed at 298 K by changing volume ratios (Vorg/V) between water and oDCBz phases, where “org” shows an organic phase. Simultaneously, an analytic equation with the Vorg/V variation was derived in order to analyze such distribution systems. Additionally, the AgPic distribution into nitrobenzene (NB), dichloromethane, and 1,2-dichloroethene (DCE) and the NaB(C6H5) 4 (=NaBPh4) one into NB and DCE were studied at 298 K under the conditions of various Vorg/V values. So, extraction constants (Kex) for MPic into the org phases, their ion-pair formation constants (KMA,org) for MA = MPic in the org ones, and standard distribution constants () for the M(I) transfers between the water and org bulk phases with M = Ag and Li-Cs were determined at the distribution equilibrium potential (dep) of zero V between the bulk phases and also the Kex (NaA), KNaA,org, and values were done at A-=BPh-4. Here, the symbols Kex, KMA,org, and or were defined as [MA] org/[M+][A-], [MA] org/[M+]org [A-]org, and [M+]org/[M+] or [A-]org/[A-] at dep = 0, respectively. Especially, the ionic strength dependences of Kex and KMPic,org were examined at M = Li(I)-K(I) and org = oDCBz. From above, the conditional distribution constants, KD,BPh4 and KD,Cs, were classified by checking the experimental conditions of the I, Iorg, and dep values.
基金Project supported by the National Natural Science Foundation of China and the Special DoctoralFund of the Chinese Education Committee.
文摘This paper has improved Hickman's nonadiabatic collision model by substituting Hickman's constant velocity classical straight line trajectory approximation with the solution of motion equation mR=-dV(R)/dR, and has calculated the cross sections of ion-pair formation Cs+O2 -Cs++O2- with the improved nonadiabatic collision model (INCM). A comparison of our results with other theoretical and experimental results has been made.
文摘For the Na + I2 collision system, theoretical study is performed on the QCISD(T) level by using ab initio method. The ab initio potential energy surfaces are got and on them the long-lived complexes are found and optimized. These results verify the crossed molecule beam experimental phenomenon and the detailed geometry structures are given for the first time. The role of the complexes in the reaction path is also described in detail.
文摘CdI2 in water was extracted with 18-crown-6 ether (L) into 10 diluents at 298 K. The following equilibrium constants were determined or evaluated: some extraction constants (Kex/mol-3·dm9 & Kex,ip/mol-2·dm6 for CdLI2, Kex±/mol-2·dm6 for CdLI+ with I-, & Kex2±/mol-1·dm3 for CdL2+ with 2I-), conditional distribution constants (KD,I for I-, KD,CdLI for CdLI+, & KD,CdL for CdL2+) between the two phases, and an ion-pair formation constant (K1,org/mol-1·dm3) for CdLI+ and that (K2,org/mol-1·dm3) for CdLI2 in the organic (org) phases. Using the K1,org and K2,org values, acidities of the complex ions, CdL2+ and CdLA+ (A- = I-, Br-, & Cl-), in the 11 diluents were classified by applying the HSAB rule. Especially, the CdLA+ ions were classified as the soft acids in 9 diluents. Also, molar volumes (Vj/cm3·mol-1) of j = CdLI2 and CdL2+ were determined with the regular-solution-theory plot of logKex,ip vs. logKD,L and its pseudo-plot of logKD,CdL, respectively. Here, KD,L denotes the distribution constant of L between the two phases. So, sizes among CdLA2 and CdL2+ were compared by using the Vj values. Additionally, some distribution equilibrium potentials (dep/V) between the water and org bulk phases were topically calculated from an equation of KD,I with KSD,I, where the symbol KSD,I shows a standard distribution constant of I- at dep = 0 V for a given diluent.
基金National Science Foundation of China(Nos.21701145 and 21701146)China Postdoctoral Science Foundation(Nos.2017M610459 and 2018T110739)。
文摘Aprotic Li-CO_(2)batteries have attracted growing interest due to their high theoretical energy density and its ability to use green house gas CO_(2)for energy storage.However,the poor ability of activating CO_(2)in organic electrolyte often leads to the premature termination of CO_(2)reduction reaction(CO_(2)RR)directly.Here in this work,cetyl trimethyl ammonium bromide(CTAB)was introduced into a dimethyl sulfoxide(DMSO)based Li-CO_(2)battery for the first time to enhance the CO_(2)RR.Significantly improved electrochemical performances,including reduced discharge over-potential and increased discharge capacity,can be achieved with the addition of CTAB.Ab initio molecular dynamics(AIMD)simulations show that quaternary ammonium group CTA^(+) can accelerate CO_(2)reduction process by forming more stable contact ion pair(CIP)with CO_(2)^(–),reducing the energy barrier for CO_(2)RR,thus improving the CO_(2)reduction process.In addition,adding CTA^(+) is also favorable for the solution-phase growth of discharge products because of the improved migration ability of stable CTA^(+)-CO_(2)^(–) CIP in the electrolyte,which is beneficial for improving the utilization ratio of cathode.This work could facilitate the development of CO_(2)RR by providing a novel understanding of CO_(2)RR mechanism in organic system.
文摘An extended LCAC\|SW(Linear Combination of Arrangement Channels\|Scattering Wavefunction) quantum scattering dynamic method combined with \%ab initio\% quantum chemical calculations has been used to study the formation mechanism of the resonance states for ion\|pair formation reaction Na+I\-2 Na\+++I\+-\-2. Resonance energy and width or lifetime for the first resonance peak were calculated. Resonance can be identified to Feshbach resonance and the physical interpretation was given.
