Das Mischungsverh?ltnis der Lithiumisotopen 7Li und 6Li

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F2 Σ+ -X 2Σ +Band System of Cobalt Carbide

The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm-1 to 22000 cm-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with methanol under supersonic jet cooled conditions. Much of the visible spectrum was assigned to transitions between the X2∑+ ground state and F2∑+ state. The 11 bands assigned as (v’=3-13, 0) transitions of the F2∑+- X2∑+ band system were observed and rotationally analyzed. Equilibrium constants for the F2∑+ state were Te=1362 cm-1, ωe=669 cm-1 ,ωe?e=4.3 cm-1, Be=0.546 cm-1, and Re=1.758A. Some new bands were observed.     

12,52-二羟基-15,55-二甲基-14,16,34,36,54,56,74,76-八硝基-2,4,6,8-四氧桥连-1,3,5,7（1,3）-杯[4]芳烃的合成

以1,5-二氟-2,4-二硝基苯和3,4,5-三甲氧基甲苯为起始原料,经环化、甲基化、硝化和去甲基化反应，合成了一种新型杯芳烃衍生物，其结构经¹H NMR，¹³C NMR，¹⁵N NMR和元素分析表征。      

Separation of Yb as YbSO4 from the 176Yb target for production of 177Lu via the 176Yb(n, γ)177Yb→177Lu process

An effective and simple process for the separation of ¹⁷⁷Lu from neutron-irradiated Yb targets was developed. Irradiated Yb target was dissolved in H₂SO₄ solution and after reduction with sodium amalgam Yb was precipitated in the form of YbSO₄. From 50 mg of Yb irradiated target only 1 mg Yb remains in solution after precipitation and separation of YbSO₄. The overall recovery of ¹⁷⁷Lu is estimated at 73%. Further efficient chromatographic separation of carrier-free ¹⁷⁷Lu from 1 mg of Yb is relatively easy and is described in several papers.     

Zur Darstellung von 109Pd, 72Ga und 51Cr hoher spezifischer Aktivit?t zieht

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情绪化学*

喜怒哀乐、积极消极、兴奋疲惫······种种情绪仿佛都源于我们所遇到的人事物,但从生命物质作用关系的角度去看待,其实是身体因为外部诱因和氛围应激产生的一系列化学物质与化学转化带来的表达。在外部事件的触发下,激素和神经递质(化学信使)这些化合物引起我们感受到某种情绪;不同情绪的产生,又会进一步反馈激发身体内相应物质的分泌。本文阐述了各种情绪和与之相关的化学分子之间的对应关系、转化关系和溯源关系。     

Synthesis and structure of the platinum complexes [Bu4N]+[PtBr5(DMSO)]?, [Ph4P]+[PtBr5(DMSO)]?, and [Ph3(n-Am)P]+[PtBr5(DMSO)]?

The complexes [Bu₄N]₂⁺[PtBr₆]²⁻ (I), [Ph₄P]₂⁺[PtBr₆]²⁻ (II), and [Ph₃(n-Am)P]₂⁺ (III) are synthesized by the reactions of tetrabutylammonium bromide, tetraphenylphosphonium bromide, and triphenyl(n-amyl)-tetraphenylphosphonium bromide, respectively, with potassium hexabromoplatinate (mole ratio 2: 1). After recrystallization from dimethyl sulfoxide, complexes I, II, and III transform into [Bu₄N]⁺[PtBr₅(DMSO)]⁻ (IV), [Ph₄P]⁺[PtBr₅(DMSO)]⁻ (V), and [Ph₃(n-Am)P]⁺[PtBr₅(DMSO)]⁻ (VI). According to the X-ray diffraction data, the cations of complexes IV–VI have a slightly distorted tetrahedral structure. The N-C and P-C bond lengths are 1.492(7)–1.533(6) and 1.782(10)–1.805(10) ?, respectively. The platinum atoms in the mononuclear anions are hexacoordinated. The dimethyl sulfoxide ligands are coordinated with the Pt atom through the sulfur atom (Pt-S 2.3280(18)–2.3389(11) ?). The Pt-Br bond lengths are 2.4330(6)–2.4724(6) ?.     

13C NMR spectra of coordinated propargyl cations [Cp2Mo2(CO)4(μ-η2,η3-(HC≡CCR1R2)]+ BF4/?

A strong deshielding effect is observed for the carbon signal of carbocation center (C⁺) in the ¹³C NMR spectra of coordinated propargyl cations [Cp₂Mo₂(CO)₄(μ-η²,η³-(HC≡CCR¹R²)]⁺ BF₄⁻ (R¹ = R² = H) 1, (R¹ = Me, R² = H) 2, and (R¹ = R² = Me) 3 when hydrogen is replaced by methyl; the effect increases with the Mo-C⁺ distance (75.37, 98.3, and 148.68 ppm for compounds 1, 2, and 3, respectively). This indicates that the back-donation of electron density from the metal onto the ligand makes a substantial contribution to the stabilization of these cations. Original Russian Text ? I.V. Barinov, V.A. Chertkov, 2009, published in Vestnik Moskovskogo Universiteta. Khimiya, 2009, No. 1, pp. 29–34.     

Rotational Analysis of A2Πu-X2Σ+g System of 14N2+

The absorption spectrum of N₂⁺ has been studied using optical-heterodyne velocity mod-ulation spectroscopy in the near-infrared region. The observed spectral lines were assigned to the (3,1), (4,2), (5,3), (8,5) bands of the A²Π_u-X²Σ⁺_g system and the line lists were provided. The (5,3) band was studied for the first time. Fourteen rotational-resolved bands in literatures were fitted together with our observed bands and the molecular constants were obtained for υ_A=0-9 and υ_X=0-5.     

Radiometrische Titrationen mit [60Co(CN)6]3?-Ionen

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64Cu放射性药物化学

64Cu半衰期为12.7 h,其衰变过程既发射β+粒子(β+,0.655 MeV,17.8%),又发射β-粒子(β-,0.573 MeV,38.4%)。近20年来,随着铜配位化学的发展,新型配体不断出现(如DOTA、TETA、NOTA、CB-TE2A、C3B-DO2A等)。Cu(Ⅱ)的络合物在生物体内/外的稳定性不断提高,64Cu已经成功标记在氨基酸、多肽、蛋白、核酸等分子以及纳米颗粒上。64Cu可制成正电子显像药物用作诊断,同时也有发展为放射性治疗药物的潜力。新型铜配体和标记方法以及新的药物靶标的研究已经成为64Cu放射性药物研究的热点,至今已研制出了多种64Cu标记的放射性药物,如64Cu-ATSM是有效的肿瘤乏氧显像剂,64Cu-PTSM是优良的血流示踪剂等。本文旨在介绍64Cu(Ⅱ)几种主要类型的含氮配体以及64Cu标记的放射性药物在显像和治疗方面的最新研究进展,并展望其发展趋势。     

硫的同素异形体*

硫是固态同素异形体数量最多的元素。但就单质硫的同素异形体而言,教材中并没有详细概述。根据硫化学的研究进展,全面考察了硫的同素异形体的种类,讨论了它们的制备、晶体结构及其相互转化,着重体现了科学技术对其同素异形体扩展的重要作用,完善了硫同素异形体在教学中的深入介绍。同时,也体现了科学研究对本科教学内容改革的推进作用。     

毒品与化学*

毒品与化学的种种纠葛在2018年中国毒品形势报告中得到了淋漓尽致的体现,因此为做好禁毒工作,必须厘清化学与毒品的关系。从为什么毒品是化学品(毒品的本质),毒品检验和识别,毒品成瘾的本质,由传统毒品到新型毒品的转变等4个方面系统阐述毒品与化学的关系。     

Tr?gerfreies 144Praseodym

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Measurements of the thermal neutron cross-sections and resonance integrals for 186W (n,γ) 187W and 98Mo (n,γ) 99Mo reactions

The thermal neutron cross-sections and resonance integrals of the ¹⁸⁶W (n,γ) ¹⁸⁷W and ⁹⁸Mo (n,γ) ⁹⁹Mo reactions in the thermal and 1/E regions, respectively, of a thermal reactor neutron spectrum have been experimentally determined by the activation method using ¹⁹⁷Au (n,γ) ¹⁹⁸Au reaction as a single comparator. The high purity natural W, Mo, and Zr foils; and Au wire diluted in aluminum, were irradiated without Cd shield in two neutron irradiation sites, characterized with different values for the thermal-to-epithermal flux ratios, f at the Second Egyptian Research Reactor (ETRR-2). The induced activities in the samples were measured by high-resolution γ-ray spectrometry with a calibrated germanium detector. Thermal neutron cross-sections for 2200 m/s neutrons and resonance integrals for the ¹⁸⁶W (n,γ) ¹⁸⁷W and ⁹⁸Mo (n,γ) ⁹⁹Mo reactions have been obtained relative to the reference values, σ₀ = 98.65 ± 0.09 b and I ₀ = 1500 ± 28 b for the ¹⁹⁷Au (n,γ) ¹⁹⁸Au reaction. The necessary correction factors for thermal neutron and resonance neutron self-shielding effects, and the epithermal flux index (α) were taken into account in the determinations. The results obtained were: σ₀ = 38.43 ± 0.4 b and I ₀ = 502 ± 65 b for ¹⁸⁶W (n,γ) ¹⁸⁷W, and σ₀ = 0.137 ± 0.014 band I ₀ = 6.47 ± 0.8 for ⁹⁸Mo (n,γ) ⁹⁹Mo. These results are discussed and compared with previous measurements and evaluated data in literature. The traditional method of determining thermal cross-sections and resonance integrals via neutron irradiation with and without Cd shield in one irradiation position was avoided in this work by neutron irradiation without Cd shield in at least two different neutron irradiation positions. This method provides alternative way for determining thermal cross-sections and resonance integrals simultaneously.     

基于竞争配位的Ca2+特异性响应1H/19F磁共振成像分子探针

合成了一种含~(19)F的Mn~(2+)配合物3,12-二(2-氧代-2-((2,2,2-三氟乙基)氨基)乙基)-6,9-二氧杂-3,12-二氮杂十四烷酸锰(Ⅱ)(Mn(Ⅱ)-L,1),可实现对Ca~(2+)特异响应的~1H/~(19)F磁共振成像分析。~(19)F核在近距离的顺磁性Mn~(2+)影响下产生了顺磁弛豫增强作用,使~(19)F的横向弛豫时间T_2急剧缩短而磁共振信号锐减。当有Ca~(2+)存在时,与配体L的竞争配位使得~(19)F远离Mn~(2+)离子,从而~(19)F磁共振信号得到恢复。同时,由于Mn~(2+)离子从配合态变为游离态,水配位数增加使得其对~1H的纵向弛豫时间T_1弛豫性能增加,从而~1H磁共振成像信号也增强。相关实验的结果证实了该配合物是一种能对Ca~(2+)特异性响应的~1H/~(19)F磁共振成像探针。     

C4H（2Σ+）+H2反应机理的直接动力学研究

贫氢分子CnH是燃烧火焰、行星大气中的重要的中间体.这些分子与其它一些分子或自由基的反应在星际化学中起着非常重要的作用.虽然这些分子的电子结构和光谱性质已经进行了广泛的研究,但是研究这些反应的机理和动力学性质也是亟需的.因此,我们采用直接动力学方法对线性分子丁二炔自由基C4H(CCCCH)夺氢气(H2)分子中HAT的反应的微观机理和动力学性质进行了理论研究.本研究分别在BB1K/6-311+G(2d,2p),B3LYP/6-311+G(2d,2p)和M06-2x/6-311+G(2d,2p)水平上优化得到了各稳定点的结构及振动频率.为了得到更为可靠的反应能量和势能面信息,在BB1K/6-311+G(2d,2p)优化结构的基础上用CCSD(T)/aug-cc-pVTZ水平进行了单点能量校正.对于此反应研究了两条不同的氢吸附通道,C4H(C1C2C3C4H)中的C1和C4分别吸氢,即通道1(R1)和通道2(R2).计算得出:通道1和通道2的能垒分别为3.58 kcal/mol和26.56 kcal/mol,结果表明C4H中C1端吸氢是主要通道.反应过程中的电子转移可以为理解氢原子转移(HAT)提供重要的线索,因此,我们利用NBO对反应过程中的电子转移行为进行了详细的分析.本工作运用经典过渡态理论(VTST)与变分过渡态理论(CVT)和变分过渡态理论结合小曲率隧道效应校正(CVT/SCT)的方法计算了该反应在40～1000 K温度区间的速率常数.除对于最低频率的配分函数采用了阻尼内转动近似外,其它频率都采用谐振子模型处理.计算得到的总的CVT/SCT反应速率常数与已有的实验值符合得很好.我们还提供了40～1000K温度范围内的三参数Arrhenius表达式.这些公式有利于今后在较宽的温度范围内迄今没有实验数据的反应的研究.     

Synthesis and structure of gold and copper complexes: [Ph3PhCH2P]+[AuCl4]?, [NH(C2H4OH)3]+[AuCl4]? · H2O, and [Ph3EtP] 2+ [Cu2Cl6]2?

Triphenylbenzylphosphonium tetrachloroaurate (I) and triethanolammonium tetrachloroaurate hydrate (II) were prepared by reacting tetrachloroauric acid in acetone with triphenylbenzylphosphonium and triethanolammonium, respectively. Triphenylethylphosphonium hexachlorodicuprate (III) was synthesized from triphenylethylphosphonium chloride and copper chloride in acetone. The crystal structures of complexes I to III were determined by single-crystal X-ray diffraction. The phosphorus atoms in complex I have a nearly undistorted tetrahedral coordination (CPC, 108.3°–110.6°; P-C, 1.788–1.793 ?). The coordination of nitrogen atoms in the cations of complex II is a distorted tetrahedron (CNC, 111.7°–112.4°). The square coordination of aurum in I and II is only slightly distorted: the ClAuCl angles are 89.6°–90.3° (I) and 89.5°–90.6° (II) and the Au-Cl distances are 2.256–2.278 ? I) and 2.280–2.285 ? (II). The phosphorus atoms in complex III are tetracoordinated (CPC, 106.34°–111.73°; P-C, 1.790–1.795 ?). The copper atoms in III have a distorted tetrahedral coordination (ClCuCl, 98.48°–144.85°; Cu-Cl, 2.1999–2.3263 ?). The central fragment Cu₂Cl₂ in the anion of complex III is bent relative to the Cu₂ axis (the chlorine atom deviates from the Cu₂Cl plane by 0.27 ?).     

1,2,3,4,7-Pentamethylindenyl complex [(η5-C9H2Me5)RhI2]2 as a synthon for the [(η5-C9H2Me5)Rh]2+ fragment

The reaction of the iodide complex [(η⁵-C₉H₂Me₅)RhI₂]₂ (1) or the acetonitrile complex [(η⁵-C₉H₂Me₅)Rh(MeCN)₃]²⁺ with Tl[Tl(η-7,8-C₂B₉H₁₁)] afforded rhodacarborane (η⁵-C₉H₂Me₅)Rh(7,8-C₂B₉H₁₁) (2). The cationic triple-decker complex with the bridging boratabenzene ligand [Cp*Fe(μ-η:η-C₅H₃Me₂BMe)Rh(η⁵-C₉H₂Me₅)]²⁺ (3) was synthesized by the reaction of the nitromethane solvate [(η⁵-C₉H₂Me₅)Rh(MeNO₂)₃]²⁺ with the sandwich compound Cp*Fe(η-C₅H₃Me₂BMe). The structure of 2 was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1623–1625, August, 2008.     

BF分子X1Σ＋, A1P和B1Σ＋态的势能函数

使用SAC/SAC-CI和D95＋＋, 6-311＋＋g, 6-311＋＋g**及D95(d)基组, 分别对BF分子的基态X¹Σ^＋、第一简并激发态A¹Π和第二激发态B¹Σ^＋的平衡结构和谐振频率进行优化计算. 对所有计算结果进行比较, 得出6-311＋＋g**基组为最优基组. 运用6-311＋＋g**基组和SAC方法对基态X¹Σ^＋, SAC-CI方法对激发态A¹Π和B¹Σ^＋进行单点能扫描计算, 并用正规方程组拟合Murrell-Sorbie函数, 得到相应电子态的势能函数解析式, 由得到的势能函数计算了与X¹Σ^＋, A¹Π和B¹Σ^＋态相对应的光谱常数, 结果与实验数据较为一致.