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1.
用光电子成像技术和从头算法研究Ag-(CH3OH)x (x=1, 2)和AgOCH3-. 从AgOCH3-振动分辨的光电子谱得 到AgOCH3-的绝热和垂直电离能分别为1.29(2)和1.34(2) eV. Ag-(CH3OH)1,2相似文献   

2.
描述了包含共线的光电子速度成像仪,以及与双阀激光溅射团簇源联用的时间飞行质谱装置.为了避免预混气体,两个脉冲阀和一个反应通道被用来产生反应负离子.共线的光电子成像仪采用了改进的速度成像透镜系统,它的能量分辨率优于3%.此外还报道了Si4-团簇在532和355 nm,以及Si3C- 团簇在532 nm的光电子速度成像.从实验图像中可以获得光电子能谱和各向异性参数.从Si4-团簇能谱上获得了中性的Si4团簇的基态和第一激发态的振动频率分别为330和312 cm-1.初步的实验结果证明这套光电子成像装置对研究团簇负离子的电子结构以及光脱附动力学非常有效.  相似文献   

3.
利用激光溅射制备了ZrO-双原子阴离子,测量了其光电子成像谱.实验观测到的光电子能谱可以在光学光谱和高精度从头计算的基础上得到很好的归属.ZrO-的基态确定为2△态,其自旋-轨道分裂能为578±12 cm-1,ZrO的电子亲和能测定为1.249±0.005 eV.第一次在实验上观测到ZrO的c3-激发态,其相对于X1+基态的能量为13316±24 cm-1,同时还对ZrO与其等电子体NbN的电子结构进行了比较.  相似文献   

4.
应用光电子成像技术研究了LaO-、CeO-、PrO-和NdO-.从1064 nm的振动分辨的光电子能谱得到LaO、CeO、PrO和NdO的电子亲和能分别为0.99(1)、1.00(1)、1.00(1) 和1.01(1) eV. 密度泛函计算和NBO分析显示镧系原子的4f电子趋于定域在4f轨道上,不受分子电荷状态的影响. 脱附的光电子主要来自镧系金属的6s轨道. 配位场理论的纯离子模型假设仍然是分析镧系一氧化物中性或负离  相似文献   

5.
在自制的负离子速度成像装置上发展了负离子质谱技术.测量获得了电子贴附解离邻位二氯苯产物Cl-的0.2~8 eV效率谱,并且在两个峰位1.2和6.0 eV测量了其切片速度影像.  相似文献   

6.
唐小锋  牛铭理  周晓国  刘世林 《物理学报》2010,59(10):6940-6947
对电子和离子同时采用速度聚焦电场收集的阈值光电子-光离子符合成像谱仪能够有效提高电子的收集效率和能量分辨率.利用该符合成像谱仪,开展了Xe/Ar/Ne 惰性混合气体及NO 分子的阈值光电子谱、阈值光电子-光离子符合质谱和质量选择的符合光谱等实验研究,精确测量了NO 分子的电离势,并且获得了NO+离子振动态分辨的X1Σ+,c3ΠB1相似文献   

7.
通过碳酸钙、γ-三氧化二铝、氯化钙在氯气/氩气混合气气氛下的固态反应制备了一种氯负离子存储-发射功能材料[Ca24Al28O64]4+·(Cl-)3.80(O2-)0.10(C12A7-Cl-).通过离子色谱、电子顺磁共振、拉曼光谱验证,C12A7-Cl-材料中存储的负离子主要是氯负离子,浓度为(2.21±0.24)×1021 cm-3,此外还有小部分的氧二价负离子、氧负离子、氧分子负离子.这与通过飞行时间质谱得到的结果一致:从C12A7-Cl-材料表面发射出的负离子主要是氯负离子(大约90%),还有小部分的氧负离子和电子.材料结构和表观变化分别由X射线衍射和场发射扫描电子显微镜表征  相似文献   

8.
利用时间分辨的飞秒光电子影像技术结合时间分辨的质谱技术,研究了2,6-二甲基吡啶分子锥形交叉超快动力学过程. 2,6-二甲基吡啶分子吸收266 nm泵浦光从基态跃迁至S2态(π-π*). 母体离子时间变化曲线包含两个指数函数,一个是时间常数为635 fs的快速组分,另一个是时间常数为4.37 ps的慢速组分. 通过时间分辨光电子影像得到的时间依赖的光电子角度分布和能量分辨的光电子谱分布提供了S2态演变的动力学信息. 简言之,快速组分反映了通  相似文献   

9.
用光电子成像技术研究了Cu-的飞秒双光子光脱附过程.光脱附产生的光电子能量分布和角度分布通过光电子成像直接获得.实验发现,在光强为6.0×1010 W/cm2下,双光子光脱附通道的光电子角度分布随激光波长出现剧烈的变化.通过低阶微扰理论和实验结果对比分析,Cu-的双光子脱附产生的光电子角度分布特征可以归结于脱附过程中Cu-的s和d轨道波函数之间的干涉效应.通过分析光电子角度分布特征,获得了不同波长下s和d轨道波函数对双光子脱附过程的贡献,该结果符合Wigner阈值理论的预期.  相似文献   

10.
本文采用尺寸选择的负离子光电子能谱与高精度理论计算,对AlnC4-/0(n=2∽4))团簇的结构和成键性质进行了研究. Al2C4-团簇负离子的最稳定结构是一个C2v对称的平面结构,其中两个C2单元与两个铝原子分别相连. Al2C4-团簇负离子的次稳定结构是一个线型结构,两个铝原子位于C4线型结构两端,能量仅比最稳定结构高0.05 eV. 中性Al2C4团簇是一个线型结构. Al3C4-团簇负离子是一个平面结构,其中三个铝原子分别与两个C2单元相连. 而中性Al3C4团簇则是一个V字型结构. Al4C4-团簇负离子和中性Al4C4团簇均为C2h对称的平面结构,四个铝原子分别位于两个C2单元的末端. AlnC4-/0(n=2∽4))团簇负离子的自适应自然密度配分的分析结果表明这些团簇中铝原子与C2单元之间的化学键具有σ和π键特征.  相似文献   

11.
Gaseous dibenzo-7-phosphanorbornadiene P-sulfide anions APS-(A=C14H10 or anthracene) were generated via electrospray ionization, and characterized by magnetic-bottle photoelectron spectroscopy, velocity-map imaging (VMI) photoelectron spectroscopy, and quantum chemical calculations. The electron affinity (EA) and spin-orbit (SO) splitting of the APS· radical are determined from the photoelectron spectra and Franck-Condon factor simulations to be EA=(2.62±0.05) eV and SO splitting=(43±7) meV. VMI photoelectron images show strong and sharp peaks near the detachment threshold with an identical electron kinetic energy (eKE) of 17.9 meV at three different detachment wavelengths, which are therefore assigned to autodetachment from dipole-bound anion states. The B3LYP/6-31++G(d,p) calculations indicate APS· has a dipole moment of 3.31 Debye, large enough to support a dipole-bound electron.  相似文献   

12.
We report a joint photoelectron spectroscopic and theoretical study on the molecular anion, quinoline?. Analysis of the vibrationally resolved photoelectron spectrum found the adiabatic electron affinity, EAa(C9H7N), to be 0.16 ± 0.05 eV. These findings were supported by density functional theory calculations. Our experimental and computational results demonstrate the unusual electrophilicity for a polycyclic aromatic heterocycle.  相似文献   

13.
The electronic structures of HCN and DCN have been determined by examining high resolution He(I) photelectron spectra of HCN and DCN, He(II) photoelectron spectrum of HCN, and the electron impact energy loss spectra of HCN and DCN. The present investigation supports an earlier assignment of the orbital sequence in HCN. New vibrational data are presented and the Rydberg series and valence transitions are reinvestigated. The adiabatic ionization energies for the 1π and 5σ orbitals in HCN are found to be 13.607 ± 0.002 eV and 14.011 ± 0.003 eV respectively.As mentioned above the investigation of the Rydberg series indicated that the first IP at 13.607 eV is the 1π ionization and the second IP at 14.011 eV is the 5σ ionization. A comparison of the experimental and theoretical intensity ratio between the two first PES progressions also supports this assignment. It is further supported by the fact that in the second IP the ν3 vibration frequency is not changed as much as it is in the first IP, which is in agreement with the PES of N2 and CO. The analysis of the bending vibrations also supports this ordering of the orbitals.The same orbital assignment has recently been proposed by Frost et al.5, using a comparison with the HCP photoelectron spectrum. The present paper supports their assignment of orbitals and (0000)-(0000) transitions. There are, however, some disagreements concerning the vibrational analysis. This is probably due to the fact that the HCN spectrum of Frost et al.5 revealed less structure than ours. As indicated by Figure 5 there is possibly still more structure to be revealed.  相似文献   

14.
The 364-nm negative ion photoelectron spectra of XO and OXO molecules (X=Ni, Pd, and Pt) are reported. The spectra yield the electron affinities (EAs): EA(NiO)=1.455±0.005 eV; EA(PdO)=1.672±0.005 eV; EA(PtO)=2.172±0.005 eV; EA(ONiO)=3.043±0.005 eV; EA(OPdO)=3.086±0.005 eV; EA(OPtO)=2.677±0.005 eV. In addition, for the diatomics, transitions from the anion X?2Π3/2 and X?2Π1/2 states into neutral X?3Σ, 3Π, and for NiO and PdO, 1Π, are assigned. Several states have been reassigned from those in the existing literature. Anion 2Π3/2-2Π1/2 spin-orbit splittings are measured, as are neutral 3Π2-3Π1 spin-orbit splittings: the XO 3Π 2-3Π1 splittings increase from 405±30 cm−1 (NiO) to 805±30 cm−1 (PdO) to 3580±40 cm−1 (PtO). A bond length shortening of 0.03±0.01 Å is measured upon electron detachment from NiO, resulting in an anion bond length of 1.66±0.01 Å. The bond length does not change upon electron detachment from PdO using 3.4-eV photons. The Pt-O bond length decreases by 0.035±0.010 Å in the 3Π12Π3/2 transition. The spectrum of OPtO displays a significantly more extended vibrational progression than those of ONiO or OPdO, and the O-Pt bond length is found to decrease by 0.07±0.01 Å upon electron detachment. The spectra support the view that the Ni-O bond is largely ionic, the Pd-O bond is somewhat less so, and the Pt-O bond displays a substantial covalent character.  相似文献   

15.
杨少鹏  傅广生  李晓苇  耿爱从  韩理 《物理学报》2003,52(11):2649-2654
为了描述在晶体生长阶段掺入[Fe(CN)64-的立方体AgCl微晶中 光电子的产生与 衰减过程,建立了一种由三个固有中心和一个浅电子陷阱(SETs)组成的动力学模型,并引出一组微分方程.通过求解微分方程得到与实验结果相符合的光电子衰减曲线及其寿命.调整相 关模拟参数,于常温下得到由[Fe(CN)64-引入的SETs阱深为0.1 15eV,电子俘获截面为2.136×10-17cm2. 关键词: 光电子 浅电子陷阱 俘获截面 AgCl微晶  相似文献   

16.
《光谱学快报》2013,46(6):633-641
Abstract

X‐ray photoelectron spectroscopy (XPS) has been used for the first time to study the composition of calcium oxalate (CaOxa) stones and uric acid stones. This technique allows for the identification and location of various inorganic and organic species at the same time. In CaOxa stones, there were less than 10% of phosphates. Sectional analyses of these stones indicated that the content of phosphorus in the stone center is higher than that in stone crust. In uric acid stones, CaOxa was rarely found. XPS is able to detect differences in chemical functionality. In uric acid stones, the binding energy (E b) for nitrogen atoms were about 399.5 ± 0.2 eV, which are largely characteristic of organic nitrogens N (?3). In comparison, the E b values of N (+5) in inorganic compounds are about 401 eV.  相似文献   

17.
利用同步辐射角分辨光电子能谱(SRARPES)对6H-SiC(0001)-6[KF(]3[KF)]×6[KF(]3[KF)] R30°重构表面的电子结构和表面态进行了研究.通过鉴别价带谱中来自于体态的信息,可以推断出重构表面的费米能级位于体态价带顶之上(2.1±0.1)eV处.实验测出的体能带结构与理论计算的结果较为符合.在重构表面上发现三个表面态,分别位于结合能-0.48 eV(S0),-1.62 eV(S1)和-4. 关键词: 角分辨光电子能谱 碳化硅(SiC) 电子结构 表面态  相似文献   

18.
In the present study we investigate free electron attachment to the amino acid valine. Mass spectra and anion efficiency curves are measured in the electron energy range from about zero eV to about 15 eV and the anionic fragments are analyzed with a double focusing mass spectrometer. The high sensitivity of the present setup allows the detection of 10 fragment anions that have not been reported before and the high mass resolution of our sector field mass spectrometer allows us the separation and identification of isobaric anions. Thus the isobaric ion pairs, CN-/C2H2-_2^-, and O-/NH2-_2^-, can be identified and assigned to individual resonances. For some of the heavier fragment anions formed we have studied collision induced dissociation to collect more information on the structures of these anions.  相似文献   

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