Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sam...Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.展开更多
The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using ...The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.展开更多
Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. Fo...Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. For cluster ion MnxOy with x >5, the mean valences of Mn atom in cluster MnxOy, ions is 2.4±0.1, and is almost unchangeable with the size of cluster from x=5-25. The relative intensity of the observed peaks with the same x but different y, can be well fitted by a binomial distribution, for x= 5-12 clusters. All the observed information indicate a gas-phase MnO, MnO2 molecule aggregation mechanism for the production of these oxygen-rich cluster ions.展开更多
In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At t...In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At the variation range of the collision energies, the excitation functions can be taken asaR(ET) De In(1 + QMAX/ET)"where ET and QMAX are the coilision energy and the reaction exoergic energy, respectively,and n is a parameter which is correlative to the Illnner of the active vibrational modes in radical R during the reaction processes. Tab1e 2 gives the paramters of the excitation fUllctions for these reactions.展开更多
团簇是由原子或分子组成的聚合体,它们的成键包括从弱的van der Waals力、氢键到强的离子键、金属键、共价键和配位键。在原子、分子向凝聚态转变过程中,团簇的形成和增长起着核心的作用。通常利用分子束和激光气化固体样品等动力学方...团簇是由原子或分子组成的聚合体,它们的成键包括从弱的van der Waals力、氢键到强的离子键、金属键、共价键和配位键。在原子、分子向凝聚态转变过程中,团簇的形成和增长起着核心的作用。通常利用分子束和激光气化固体样品等动力学方法可以产生各种团簇。尽管实验上可以控制产生各种团簇,但是许多团簇通常不是热力学上稳定的物种并且极易发生解离和增长反应,这样形成的一系列团簇不仅是瞬态存在的而且浓度也低,因此化学上分离团簇是比较困难的;虽然团簇的组成利用质谱方法容易指认。展开更多
文摘Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.
文摘The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.
文摘Time-of-flight mass spectrometry was used to investigate negative Mn-O clusters produced by 532 um laser vaporization of MnCO3 solid pellet. Five series MnxOy, x = 1-33, y - x= 0,1,2,3,4 cluster ions were observed. For cluster ion MnxOy with x >5, the mean valences of Mn atom in cluster MnxOy, ions is 2.4±0.1, and is almost unchangeable with the size of cluster from x=5-25. The relative intensity of the observed peaks with the same x but different y, can be well fitted by a binomial distribution, for x= 5-12 clusters. All the observed information indicate a gas-phase MnO, MnO2 molecule aggregation mechanism for the production of these oxygen-rich cluster ions.
文摘In a beam-beam scattering experAnent the excitation fUnctions of the reactions of alkallne earth metals with some polyatoAnc halldes (M+RX- MX+R) have been studied with Laser Induced Fluorescence (LIF) teclmique. At the variation range of the collision energies, the excitation functions can be taken asaR(ET) De In(1 + QMAX/ET)"where ET and QMAX are the coilision energy and the reaction exoergic energy, respectively,and n is a parameter which is correlative to the Illnner of the active vibrational modes in radical R during the reaction processes. Tab1e 2 gives the paramters of the excitation fUllctions for these reactions.
文摘团簇是由原子或分子组成的聚合体,它们的成键包括从弱的van der Waals力、氢键到强的离子键、金属键、共价键和配位键。在原子、分子向凝聚态转变过程中,团簇的形成和增长起着核心的作用。通常利用分子束和激光气化固体样品等动力学方法可以产生各种团簇。尽管实验上可以控制产生各种团簇,但是许多团簇通常不是热力学上稳定的物种并且极易发生解离和增长反应,这样形成的一系列团簇不仅是瞬态存在的而且浓度也低,因此化学上分离团簇是比较困难的;虽然团簇的组成利用质谱方法容易指认。
