M+AsF6-(M=Li,Na,K,Rb和Cs)离子对的结构和振动光谱

利用abinitio计算方法研究了AsF6-阴离子和M AsF6-(M =Li ,Na ,K ,Rb 和Cs )直接接触离子对的结构和光谱行为。结果表明,具有C3V结构三齿相互作用的M AsF6-最稳定,二齿配位的结构只有在特定条件下才可能稳定存在。当形成离子对后,阳离子与AsF6-的相互作用将改变AsF6-的结构,这其中Li 的影响最大。另外,AsF6-光谱的变化可用来指认溶液中离子的缔合和离子对的种类。     

Kei2 ECR离子源C4+、C5+束流的最佳结果

With the prototype ECR ion source for the next carbon therapy facility in Japan a new series of measurements has been performed in order(a)to find the highest beam currents of C~(4 ) ions,and(b)to study the effect of"special"gas-mixing by using a chemical compound as a feed gas.An isotopic effect has been found in a previous experiment:with deuterated methane(CD_4 gas) the C~(5 ) beam currents are about 10% higher than with regular methane(CH_4 gas).For butane gases(C_4D_(10) and C_4H_(10) respectively)the isotopic effect for C~(5 ) production is even stronger(>15%).For production of C~(4 ) ions the isotopic effect appears to be absent.It turns out that the relative amount of carbon is much more important:acetylene gives 15% higher C~(4 ) current than butane,which in turn gives about 10% higher C~(4 ) ion currents than methane.     

Vibrational Spectra and Normal Coordinate Analysis of Diamminediiodidezinc(II) with 15N and 2H Isotopic Substitution.

The Raman and IR. spectra of solid diamminediiodidezinc (II) with ¹⁵N and ²H isotopic substitution have been measured. The spectra have been interpreted assuming C_2v symmetry for the Zn(NH₃)₂I₂ complex structure. The skeletal stretching metal-ligand modes v_s(ZnN), v_as(ZnN), v_s(ZnI), v_as(ZnI) as well as the three bending modes δ(NZnN), δ(IZnI) and δ(IZnN) were assigned by comparison with the spectra of Zn(NH₃)₂C1₂ and Zn(NH₃)₂Br₂, and by the observed isotopic shifts of the frequencies. A normal coordinate analysis for the whole complex was carried out using the Local Symmetry Force Field Model.     

Dynamics for Reactions of Ion Pairs in Aqueous Solution: Reactivity of Tosylate Anion Ion Paired with the Highly Destabilized 1-(4-Methylphenyl)-2,2,2-Trifluoroethyl Carbocation

The sum of the rate constants for solvolysis and scrambling of carbon bridging and nonbridging oxygen-18 at 4-MeC(6)H(4)CH(CF(3))OS((18)O(2))Tos in 50/50 (v/v) trifluoroethanol/water, (k(solv) + k(iso)) = 5.4 × 10(-6) s(-1), is 50% larger than k(solv) = 3.6 × 10(-6) for the simple solvolysis reaction of the sulfonate ester. This shows that the ion pair intermediate of solvolysis undergoes significant internal return to form reactant. These data give a value of k(-1) = 1.7 × 10(10) s(-1) for internal return of the carbocation-anion pair to the substrate. This rate constant is larger than the value of k(-1) = 7 × 10(9) s(-1) reported for internal return of an ion pair between the 1-(4-methylphenyl)ethyl carbocation and pentafluorobenzoate anion to the neutral ester (4-MeC(6)H(4)CH(CH(3))O(2)CC(6)F(5)) in the same solvent. The partitioning of ion pairs to the 1-(4-methylphenyl)ethyl carbocation and to the highly destabilized 1-(4-methylphenyl)2,2,2-trifluoroethyl carbocation is compared and contrasted.     

低能氮离子注入固态羧酸钠的光谱分析

对２５ｋｅＶ Ｎ＾＋离子束辐照羧酸钠引起其分子结构的变化进行了研究,通过紫外光谱的分析,得到了离子注入后苯甲酸钠的残存剂量效应曲线,辐照后乙酸钠样品产生了新的具有紫外吸收的物质。傅里叶红外光谱分析证明,两种羧酸钠样品辐照后的产物中含有新的化学基团氰基。     

相对论重离子碰撞中π对相对动量分布

在π源动量分布的高斯分布下,给出了相对论重离子碰撞中非关联π对和关联π对的相对动量分布.用关联π对的相对动量分布得到球形高斯分布π源参数与椭球形高斯分布π源参数的解析关系,与相对论重离子中心碰撞1.8A GeV Ar+Pb的实验结果进行了对比.当π源温度更高时,应当用p₁(p)=N·exp(–m2+p2/T)进行计算.     

Vibrational Spectra of [Zn(15NH3)4] (ReO4)2 and [Cd(NH3)4] (ReO4)2 With 110Cd/116Cd and H/D Isotopic Substitution

The infrared spectra of the zinc tetraammine with ¹⁵N, and cadmium tetraammine perrhenates with ¹¹⁰Cd/¹¹⁶Cd and H/D isotopic substitution, provides useful data in determining skeletal pseudo - exact force constants. An approximate set of force constants in the F₂ symmetry class for the whole complexes were obtained.     

ECR离子源引出束流周期性波动研究

Earlier we reported an ion current jump which was observed at a fixed negative biased disc potential in the 6.4GHz ECR ion source at VECC,Kolkata.In a recent experiment with neon ions,we measured the time spectra of the ion current and observed the presence of a burst frequency in the kilohertz range.This frequency shows a correlated jump with the ion current jump described above.Another interesting feature is that the observed burst frequency shows a good linear correlation with the extracted ion current.The higher the ion current,the higher is the burst frequency.This means that current per burst is a constant factor;when there are more number of bursts,the current also increases.     

Calculation of Absorption Intensities of Cr3+ Ion Pair Lines in Ruby

The calculation of relative intensities of the optical absorption lines of the fourth order pair of Cr³⁺ ions in ruby has been performed assuming the electro-dipole character of the transitions.     

结合除谱,差谱,二阶差谱的二氯化铜水溶液中直接接触离子对的紫外可见吸收光谱研究

The microstructure of aqueous CuCl₂ has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the UV-visible spectra of thin film of CuCl₂/H₂O solutions at different concentrations. This method is the combination of ratio spectra, difference spectra and second order difference spectra. By using this method, two new bands at ~230 and ~380 nm are obviously observed. The bands are assigned as the contacted ion pairs[CuCl₃(H₂O)_n]^- or[CuCl₄(H₂O)_n]^2-, which demonstrates that ion pairs exist in the CuCl₂/H₂O solution. Such finding agrees with the recent theoretical spectra obtained by time-dependent density functional theory. Furthermore, the populations of the contacted ion pairs are discussed. This study not only offers the direct spectroscopic evidence of[CuCl₃(H₂O)_n]^- or[CuCl₄(H₂O)_n]^2- in aqueous CuCl₂, but also suggests that the spectroscopic analysis method is powerful to extract the weak bands in a strong overlapping spectrum.     

激光场中一维和三维氢分子离子模型经典动力学行为的比较

应用经典轨迹方法,采用辛算法数值求解激光场中的一维和三维氢分子离子(H2 )的Hamilton正则方程,得到氢分子离子在激光场作用下的经典轨迹,并比较分析氢分子离子一维模型与三维模型的存活、解离、电离和库仑爆炸等动力学行为,以及电子的运动情况的相似之处.数值结果表明,采用一维模型能近似定性反映氢分子离子的动力学行为,并且简便可行.     

Ion pair formation in the vacuum ultraviolet region of NO studied by negative ion imaging spectroscopy

The pair formation of positive and negative fragment ions has been studied in the vacuum ultraviolet region of NO, with negative ion imaging spectroscopy. The negative ion yield curve obtained in the photon energy region of 19–25 eV exhibits many structures which are absent from the photoabsorption spectrum in the same region. The partial yields and asymmetry parameters associated with the dissociations into individual ion pair limits have been extracted from the negative ion images observed. On the basis of these quantities, the assignments for the structures exhibited on the negative ion yield curve are given and the dynamical properties on the ion pair dissociation are discussed.     

H+4形成机制的初步研究

利用Penningiontrap存储和累积离子的功能,获得不同延时（即反应时间）的离子谱H+n(n≤4),不仅进一步证实了H+4具有稳定结构的理论预言,而且经分析得出,H+4是经碰撞反应H+2+H2→H+4;H+3+H+H2→H+4+H2产生的。     

H2SiCl2分子Si-H振动"基座"SiCl2的有效质量

用傅立叶变换光谱仪和激光腔内吸收光谱仪记录了H2 SiCl2 分子 2 0 0 0～ 90 0 0和 12 0 0 0～ 12 90 0cm-1的红外吸收光谱 .依据局域模理论的非谐性耦合非谐振子 (ACAO)模型 ,分析并拟合了Si-H的对称伸缩振动和反对称伸缩振动 ,得到描述Si-H伸缩振动的Morse离解能De、Morse振子参数α和键振子势能耦合系数frr′.分析中忽略了SiCl2 “基座”对Si-H伸缩振动的影响 ,拟合结果与实验值符合的很好 ,拟合方差小于 1cm-1,表明这一近似是可取的 .分析拟合结果表明 ,Si-H振动时“基座”SiCl2 的有效质量为 75 .     

Quasiclassical trajectory calculations of the isotopic effect on cross-sections of reactions O(1D) + HCl (DCl,TCl)

The paper reports on a quasiclassical trajectory (QCT) study of the O(¹D) + HCl (DCl, TCl) reactions, with emphasis on the isotopic effect on cross-sections and branching ratio. The calculations were performed on the ground 1 ¹ A' potential energy surface (PES). The cross-sections and branching ratios of the O(¹D) + HCl (DCl, TCl) reaction have been calculated at the collision energies (E _col) of 3–15 kcal/mol. Obvious differences have been found in the energy dependences of the reaction cross-sections and branching ratios among these isotopic reactions.     

中能区类弹碎片中质比的靶核相关性

基于实验测量并结合模型分析,讨论了中能区重离子周边碰撞过程中出射的类弹碎片(PLF)的中质比(N/Z)与靶核N/Z相关现象的产生原因.     

Sin-1N和Sin-2N2(n=3～8)离子团簇结构及其光电子能谱的研究

利用密度泛函理论中的B3LYP方法,在6-311G(d)基组上对Sin-1N和Sin-2N2(n=3~8)阴阳离子团簇的几何结构和光电子能谱进行了系统研究。结果得到了各团簇的最稳定结构,Sin-2N2离子团簇对称性比Sin-1N离子团簇对称性好;Sin-1N(n=3~8)离子团簇的几何结构在总原子数n≤4时为平面结构,n>4时为立体结构;Sin-2N2(n=3~8)离子团簇的几何结构在总原子数n≤6时为平面结构,n>6时为立体结构;对于Sin-1N 团簇,总原子数是偶数的团簇比总原子数为奇数的团簇稳定;对于Sin-1N-及Sin-2N2阴阳离子团簇,总原子数是奇数的团簇比总原子数为偶数的团簇稳定。     

四溴荧光素丁基罗丹明B染料离子时的吸光性质研究

本对四溴荧光素、丁基罗丹明Ｂ各自的吸光性质以及它们的形成的离子缔合物的吸光性质进行了研究。测得四溴荧光素与丁基罗丹明Ｂ在ｐＨ７时的缔合比为１：２。其Ｋｓｐ＝２．１６×１０＾－１８。缔合物的萃取率为８３．２％。为进一步研究四溴荧光素、丁基罗丹明Ｂ的萃取光度分析奠定了理论基础。     

(C_5H_(11)N_2)~+和(C_7H_(12)N_2)~(2+)的NMR研究

结合1H NMR,13C NMR谱,分别对钨、钼配合物{WO2(C10H6O2)2(C5H11N2)2[H2N(CH2)3NH2]}3(1),{(C5H11N2)2[H2N(CH2)3NH2][MoO2(C10H6O2)2]}(2),{(C7H12N2)2[MoO2(C10H8O2)2]}(3)晶体结构中小分子环进行了归属.其中,配合物1和2中(C5H11N2)+的NMR研究证实了六元环由1,3-丙二胺和乙腈化合而成,配合物3中(C7H12N2)2+的NMR谱图证实了七元环由乙二胺和乙酰丙酮化合而成,并且推导出这些亲核加成-消除反应的反应机理.配合物1~3中的小分子环的合成在其它体系中尚未见报导,而在合成它们的反应中作为新产物随主体晶体析出,并由晶体结构解析和NMR得到了证实.