Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and...Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and their possible structures were discussed.The results indicated that C60 is very reactive to electrophiles in the gas phase.展开更多
In this study,we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal plates.The opening of the extractor plate is covered withmetal mesh,which is for shielding the interac...In this study,we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal plates.The opening of the extractor plate is covered withmetal mesh,which is for shielding the interaction region of the lens system from the high DC voltages applied to all other plates than the repeller and extractor plates.The Simion simulation shows that both velocity-mapping and time focusing can be achieved simultaneously when appropriate voltages are applied to each of the plates.This makes the ion lens system be able to focus large ionic volumes in all three dimensions,which is an essential requirement for crossed ion-molecule scattering studies.A three-dimensional ion velocity measurement system with multi-hit and potential multi-mass capability is built,which consists of a microchannel plate(MCP),a P47 phosphor screen,a CMOS camera,a fast photomultiplier tube(PMT),and a high-speed digitizer.The two velocity components perpendicular to the flight axis are measured by the CMOS camera,and the time-of-flight,from which the velocity component along the flight axis can be deduced,is measured by the PMT.A Labview program is written to combine the two measurements for building the full three-dimensional ion velocity in real time on a frame-by-frame basis.The multi-hit capability comes from the fact that multiple ions from the camera and PMT in the same frame can be correlated with each other based on their various intensities.We demonstrate this by using the photodissociation of CH31 at 304 nm.展开更多
The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-mo...The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-molecule reactions were studied by using collision-induced dissociation technique. It was found that the electron-releasing groups favored the adduct reactions and the electron-withdrawing groups did not. The position and properties of substituting groups had an effect on the relative abundance of the adduct ions. The fragmentation reaction of the adduct ions formed by ortho-benzene diamine with the acetyl ion was similar to the reductive alkylation reaction of amine in condensed phase.展开更多
In chemical ionization mass spectrometry (CIMS) gas phase C60+ or C60can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions A dozen of gas-phase addu...In chemical ionization mass spectrometry (CIMS) gas phase C60+ or C60can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions A dozen of gas-phase adduct ions of C60 are observed, and most of them contain chlorine atoms The results of the comparison and analysis show that the relative intensities of adduct ions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C60+ or C60. This indicates that the alkene-like C60+ or C60 can act as a radical sponge in addition reactions.展开更多
The dissociative electron attachment process for CHCl3 at different electric field have been studied with nitrogen as drift and carrier gas using corona discharge ionization source ion mobility spectrometry （CD-IMS）...The dissociative electron attachment process for CHCl3 at different electric field have been studied with nitrogen as drift and carrier gas using corona discharge ionization source ion mobility spectrometry （CD-IMS）. The corresponding electron attachment rate constants varied from 1.26×10-8 cm3/（molecules s） to 8.24×10-9 cm3/（molecules s） as the electric field changed from 200 V/cm to 500 V/cm. At a fixed electric field in the drift region, the attachment rate constants are also detected at different sample concentration. The ionmolecule reaction rate constants for the further reaction between Cl^- and CHCl3 are also detected, which indicates that the technique maybe becomes a new method to research the rate constants between ions and neural molecules. And the reaction rate constants between Cl- and CHCl3 are the first time detected using CD-IMS.展开更多
Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward an...Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward and backward products is roughly symmetric for the title reaction. The product rotational state distribution was also determined at a few collision energies. In t, he collision energy range from 0.124 eV to 1.424 eV, the integral cross section for this system monotonically decreases with the collision energy. A comparison with the experimental result of the ion-molecule reaction was also made, the agreement is generally good.展开更多
Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(...Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(+)is the predomi-nant,and most of this product show the spatial distribution around the target,implying that the dissociation occurs in the large impact-parameter collision and via the energy resonant charge transfer.Meanwhile,a few C_(2)H_(2)Cl^(+)locate around the center-of-mass,which is at-tributed to the fragmentation of intimate association between C_(2)H_(2)Cl_(2)and Ar^(+)or in the small impact-parameter collision.The product C_(2)HCl_(+)exhibits the velocity distribution fea-tures similar to those of C_(2)H_(2)Cl_(+).The rarest product C_(2)HCl_(2)+shows the distributions around the molecular target,due to the quick dehydrogenation after the energy-resonant charge transfer in the large impact-parameter collision.展开更多
The ion-molecule reactions in acetone were investigated which were induced under the chemical ionization. The structural information of the reaction products were obtained by using collision-induced dissociation (CID)...The ion-molecule reactions in acetone were investigated which were induced under the chemical ionization. The structural information of the reaction products were obtained by using collision-induced dissociation (CID) technique performed at ion kinetic energies of 30eV.展开更多
Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical calculations.Experiments indicate that the[LnO]^(+)(Ln=Sm-Lu)io...Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical calculations.Experiments indicate that the[LnO]^(+)(Ln=Sm-Lu)ions are able to activate methane to generate methyl radicals.In particular,[EuO]^(+)and[YbO]^(+)exhibit the highest reactivity.Interestingly,ab initio computations reveal a novel HAT process operating in the absence of a terminal oxygen radical,as mediated by[EuO]^(+)and[YbO]^(+).Such a process diverges from previous findings on the methane activation by metal oxide clusters,not only on the electronic pattern during the course of hydrogen transfer,but also on the important role that 4f electrons play.The associated electronic origins have been discussed,and the well-designed 4f electron occupation may turn to be a promising approach in constructing lanthanide involved catalysts.展开更多
文摘Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and their possible structures were discussed.The results indicated that C60 is very reactive to electrophiles in the gas phase.
基金This work is supported by the Program for Young Outstanding Scientists of Institute of Chemistry,Chinese Academy of Science,and Beijing National Laboratory for Molecular SciencesHong Gao and Li-chang Guan are also supported by the K.C.Wong Education Foundation.
文摘In this study,we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal plates.The opening of the extractor plate is covered withmetal mesh,which is for shielding the interaction region of the lens system from the high DC voltages applied to all other plates than the repeller and extractor plates.The Simion simulation shows that both velocity-mapping and time focusing can be achieved simultaneously when appropriate voltages are applied to each of the plates.This makes the ion lens system be able to focus large ionic volumes in all three dimensions,which is an essential requirement for crossed ion-molecule scattering studies.A three-dimensional ion velocity measurement system with multi-hit and potential multi-mass capability is built,which consists of a microchannel plate(MCP),a P47 phosphor screen,a CMOS camera,a fast photomultiplier tube(PMT),and a high-speed digitizer.The two velocity components perpendicular to the flight axis are measured by the CMOS camera,and the time-of-flight,from which the velocity component along the flight axis can be deduced,is measured by the PMT.A Labview program is written to combine the two measurements for building the full three-dimensional ion velocity in real time on a frame-by-frame basis.The multi-hit capability comes from the fact that multiple ions from the camera and PMT in the same frame can be correlated with each other based on their various intensities.We demonstrate this by using the photodissociation of CH31 at 304 nm.
文摘The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-molecule reactions were studied by using collision-induced dissociation technique. It was found that the electron-releasing groups favored the adduct reactions and the electron-withdrawing groups did not. The position and properties of substituting groups had an effect on the relative abundance of the adduct ions. The fragmentation reaction of the adduct ions formed by ortho-benzene diamine with the acetyl ion was similar to the reductive alkylation reaction of amine in condensed phase.
文摘In chemical ionization mass spectrometry (CIMS) gas phase C60+ or C60can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions A dozen of gas-phase adduct ions of C60 are observed, and most of them contain chlorine atoms The results of the comparison and analysis show that the relative intensities of adduct ions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C60+ or C60. This indicates that the alkene-like C60+ or C60 can act as a radical sponge in addition reactions.
基金ACKNOWLEDGMENTS The work was support by the National Natural Science Foundation of China （No.20707025 and No.20907054） and the Excellent Youth Foundation of Anhui Province Scientific Committee （No.06045098）.
文摘The dissociative electron attachment process for CHCl3 at different electric field have been studied with nitrogen as drift and carrier gas using corona discharge ionization source ion mobility spectrometry （CD-IMS）. The corresponding electron attachment rate constants varied from 1.26×10-8 cm3/（molecules s） to 8.24×10-9 cm3/（molecules s） as the electric field changed from 200 V/cm to 500 V/cm. At a fixed electric field in the drift region, the attachment rate constants are also detected at different sample concentration. The ionmolecule reaction rate constants for the further reaction between Cl^- and CHCl3 are also detected, which indicates that the technique maybe becomes a new method to research the rate constants between ions and neural molecules. And the reaction rate constants between Cl- and CHCl3 are the first time detected using CD-IMS.
基金Ⅴ. ACKN0WLEDGEMENTS This work was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology and the National Natural Science Foundation of China （No.20328304, No.10574068, No.20533060 and No.20525313）.
文摘Quasi-classical trajectory （QCT） calculations on the H^＋＋H2 reaction system were carried out on a new potential energy surface （PES）. Theoretical calculations show that the angular distribution of the forward and backward products is roughly symmetric for the title reaction. The product rotational state distribution was also determined at a few collision energies. In t, he collision energy range from 0.124 eV to 1.424 eV, the integral cross section for this system monotonically decreases with the collision energy. A comparison with the experimental result of the ion-molecule reaction was also made, the agreement is generally good.
基金supported by the National Natural Sci-ence Foundation of China(No.22003062 and No.21625301)the Chinese Academy of Sciences(No.YZ201565).
文摘Dissociative charge exchange re-actions between Ar^(+)ion and trans-/cis-dichloroethylene(trans-/cis-C_(2)H_(2)Cl_(2))are investi-gated with the ion-velocity imag-ing technique.The dechlorinated product C_(2)H_(2)Cl^(+)is the predomi-nant,and most of this product show the spatial distribution around the target,implying that the dissociation occurs in the large impact-parameter collision and via the energy resonant charge transfer.Meanwhile,a few C_(2)H_(2)Cl^(+)locate around the center-of-mass,which is at-tributed to the fragmentation of intimate association between C_(2)H_(2)Cl_(2)and Ar^(+)or in the small impact-parameter collision.The product C_(2)HCl_(+)exhibits the velocity distribution fea-tures similar to those of C_(2)H_(2)Cl_(+).The rarest product C_(2)HCl_(2)+shows the distributions around the molecular target,due to the quick dehydrogenation after the energy-resonant charge transfer in the large impact-parameter collision.
文摘The ion-molecule reactions in acetone were investigated which were induced under the chemical ionization. The structural information of the reaction products were obtained by using collision-induced dissociation (CID) technique performed at ion kinetic energies of 30eV.
基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2023C01102,2023C01208)the“AI for Electrochemistry Program”of Xiamen University(RD2023100101)。
文摘Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical calculations.Experiments indicate that the[LnO]^(+)(Ln=Sm-Lu)ions are able to activate methane to generate methyl radicals.In particular,[EuO]^(+)and[YbO]^(+)exhibit the highest reactivity.Interestingly,ab initio computations reveal a novel HAT process operating in the absence of a terminal oxygen radical,as mediated by[EuO]^(+)and[YbO]^(+).Such a process diverges from previous findings on the methane activation by metal oxide clusters,not only on the electronic pattern during the course of hydrogen transfer,but also on the important role that 4f electrons play.The associated electronic origins have been discussed,and the well-designed 4f electron occupation may turn to be a promising approach in constructing lanthanide involved catalysts.
