[二苯并18冠醚6]KC60里C60的取向有序与磁相关的13C NMR研究

报道了超分子材料[二苯并18冠醚6]KC₆₀是一种具有奇异磁特性的富勒烯衍生物,经¹³C NMR研究发现,C₆₀的取向有序与磁性之间存在着很强的相关性.     

二苯并18-冠-6配合物[NH4(DB18-C-6)]2[Pd(SCN)4]的合成与结构分析

研究了二苯并18-冠-6(DB18-C-6)与(NH4)2[Pd(SCN)4]的反应,通过元素分析、红外光谱、单晶X射线衍射对生成的配合物[NH4(DB18-C-6)]2[Pd(SCN)4](1)进行了结构分析.1为三斜晶系,空间群P-1,晶体学数据:a=0.8705(3)nm,b=1.1954(4)nm,c=1.3044(4)nm,α=73.216(5)°,β=78.897(5)°,γ=81.105(6)°,V=1.2682(7)nm3,Z=1,F(000)=568,R1=0.0301,wR2=0.0431.配合物由二个[NH4(DB18-C-6)]+配阳离子和一个[Pd(SCN)4]2-配阴离子组成,二者通过N-H…N氢键形成中性配合物,配合物中不存在阳离子-π相互作用.     

二苯并-18-冠-6的合成及其光谱性质

通过改变溶剂的极性、离子性、离去基团的活性及反应温度等方法,对传统的Pedersen冠醚合成法进行了优化,使目标产物的最高产率可达71%以上,速率增加,而且反应条件温和.产物通过IR、1H NMR及元素分析等方法进行结构表征.同时对目标产物的荧光及紫外可见光谱性质也进行了初步的研究,结果表明:目标产物不仅具有较好的光谱性质,而且一些金属离子能使其荧光强度发生改变.因此我们期望目标化合物能够用于一些离子的检测、生物分子的分析.     

二苯并-18-冠-6与硫氰酸钇络合物的研究(Ⅱ)——晶体结构测定

二苯并-18-冠-6硫氰酸钇晶体为冠醚与硫氰酸钇的络合物。其分子式为C₂₃H₂₄O₆N₃S₃Y。属正交晶系,空间群为D_2h-P_mcn(标准型为P_nma)。晶胞参数a=19.885(9)?,b=17.283(8)?,C=7.942(3)?三个NCS^-的氮原子形成9配位多面体,络合物分子属C_s点群。用PW-1100四圆衍射仪收集衍射强度数据,独立衍射点为2859个。用Patterson法测定晶体结构,结构参数的修正采用准对角矩阵最小二乘法,R=0.071,由差值Fourier综合得到氢原子位置。 关键词：     

C60薄膜的离子注入损伤研究

在200 keV重离子加速器上，用120—360 keV的H,N,Ar和Mo离子注入C₆₀薄膜．对注入后薄膜的拉曼谱进行了分析．结果表明，不同离子注入C₆₀薄膜后，C₆₀的1469 cm^-1特征峰随注入剂量的增加均呈指数式下降，同时在1300—1700 cm^-1范围出现非晶碳峰，并逐渐增强，最终完全非晶化．而且1469 cm^-1拉曼峰的强度及C₆₀薄膜完全非晶化所对应的剂量与注入离子的种类和能量有关．进一步的分析表明，C₆₀分子的损伤主要是由注入离子的核能量转移所造成，与电子能量转移无关．H离子注入C₆₀薄膜后，1469 cm^-1处特征拉曼峰向短波方向非对称展宽，这可能是注入的H离子通过电子能量转移使C₆₀分子发生聚合的结果. 关键词：     

织构C60薄膜的生长与光致发光特性

用Hot Wal方法，在氟金云母单晶上生长出了（111）织构的C₆₀薄膜．用X射线衍射、Raman散射、扫描电子显微镜和原子力显微镜研究了织构C₆₀薄膜的结晶质量和结构特性．测量了织构C₆₀薄膜在室温300K和低温77K的光致发光光谱．对所得结果进行了分析与讨论 关键词：     

苯并18-冠-6配合物[K(B18-C-6)]SCN的合成与结构分析

苯并 18 -冠 - 6 (B18- C- 6 )与 K2 [Cd(SCN) 4 ]反应 ,得到了 [K(B18- C- 6 ) ]SCN配合物。通过元素分析、红外光谱、单晶 X射线衍射进行了结构分析。该配合物为单斜晶系 ,空间群 P2 (1) / c,晶体学数据 :a=0 .996 0(3) nm,b=2 .5 0 97(7) nm,c=0 .8374 (2 ) nm,β=10 6 .5 19(5 )°,V=2 .0 0 6 7(10 ) nm3 ,Z=4 ,F(0 0 0 ) =86 4,R1=0 .0 4 2 9,w R2 =0 .0 5 75。结构分析表明 ,该配合物由一个 [K(B18- C- 6 ) ]配阳离子和一个 SCN阴离子组成 ,配合物的两个分子通过 K+ - π相互作用形成一维链状结构     

C60中非线性激发的动力学研究

用电子－晶格耦合的紧束缚模型和求解实时牛顿动力学方程的方法研究了Ｃ₆₀受光激发后的动力学过程，得到了受光激发后Ｃ₆₀分子的能量，键结构和电子状态的动态演化，结果表明光激发Ｃ₆₀分子演化成环状双极化子激子。该计算结果与中性富勒烯材料的荧光实验所得出的结论一致。 关键词：     

功能染料4,4′-双(4-羧基偶氮苯)二苯并-18-冠-6的制备及其吸收光谱

以二苯并-18-冠-6和对氨基苯甲酸为原料,经重氮化、偶合等多步反应,制备了一种功能染料——4,4’-双(4-羧基偶氮苯)二苯并-18-冠-6.产率68.5%,通过IR、~1H NMR和元素分析等方法对其结构进行表征。研究了不同金属离子对目标化合物紫外一可见吸收光谱的影响,用密度泛函理论对其作用机理进行探讨。结果表明,目标化合物的吸收光谱性能良好,对稀土元素和金属汞离子具有不同作用机理的选择性识别作用。     

C60在冲击波作用下的反应研究

 采用爆轰波驱动飞片,对C₆₀样品进行冲击实验,实验产生的烟灰经甲苯萃取后,采用高效液相色谱进行成份分析。结果表明：冲击波的高温高压作用使C₆₀样品大部分分解,少部分形成高碳富勒烯、富勒烯包合物和其它碳簇产物。研究了不同冲击波作用下,C₆₀样品的压强、温度的变化及对C₆₀反应的影响,并对C₆₀的分解与聚合的作用机理进行了探讨。     

Dynamic 13C NMR spectroscopy

Dynamic ¹³C NMR spectroscopy is a recent addition to the tools available to chemists to investigate dynamic processes in molecules. The ¹³C spectra are not complicated by coupling and separation of the signals is the order of five times as large (in Hz). Consequently the temperature range over which meaningful measurements can be obtained is increased. There is therefore a marked increase in the dynamic range and accuracy of the measurements. Both very slow processes, e.g. 0.017 s^?1 for N,N-dimethylformamide and very fast processes, e.g. ΔG³ = 17.6 kJ mol^?1 for cycloocta-1,3,5-triene can be examined. In addition the technique is becoming very important in observing dynamic processes in metal carbonyls.     

1H AND 13C NMR ASSIGNMENTS OF DIOSGENYL

用同核和异核二维核磁共振方法全归属了一系列合成的薯蓣皂甙元-α-L鼠李糖基-β-D葡萄糖甙的     

13C NMR investigation of adsorbed hydrocarbons

By means of Fourier transform techniques ¹³C nmr spectra and longitudinal ¹³C magnetic relaxation times of various butene isomers sorbed on NaY and NaX zeolites have been studied. In contrast to ¹H resonance where only two broad lines can be observed, the ¹³C spectra show separated sharp lines. The shift Δσ = σ_ads-σ_free of the carbon-13 lines of adsorbed molecules with respect to the resonance positions of free molecules and the longitudinal relaxation times indicate a peculiar behaviour of the groups  CH and = C

of the adsorbed n-butene and isobutene molecules, respectively. The resonance deviations Δσ to lower fields in these groups decrease in the order isobutene (δσ = ? 10.3 ppm), but-1-ene (δσ ≈ ?5.7 ppm) and but-2-enes (Δσ ≈ ? 2.2–2.4 ppm), whereby the spectra of cis-but-2-ene and trans-but-2-ene show similar differences as found in the liquid state. When adsorbed on NaY and NaX types (silica/alumina ratios 5 and 3.5) the ¹³C nmr line positions of but-1-ene molecules are the same within the limits of experimental error, which demonstrates that electrostatic fields have no noticeable influence on the molecular parameters in these systems. Therefore one may conclude that chemical bonds to Na⁺ cations have the dominant effect on the line shift Δσ. CNDO-MO calculations based on such a model have shown that a charge transfer occurs from the π-electrons and the electrons of the methyl group hydrogen atoms to the cation.     

金银花的13C NMR指纹图谱研究

利用PFT-NMR 核磁共振波谱仪测定了金银花特征提取物的¹³C NMR图谱,对金银花提取物的¹³C NMR指纹图谱进行了解析,与其有效成分绿原酸进行了比较,获得了金银花提取物的特征峰,并比较了不同金银花的优劣. 结果表明不同金银花提取物(M1, M2, Z1, Z2)的¹³C NMR指纹图谱都显示出绿原酸的特征共振峰,并具有很好的重现性和高度的特征性,可以成为金银花真伪鉴别的依据;优质(M1, Z1)与劣质(劣质M1,劣质Z1)金银花¹³C NMR图谱的差异进一步说明¹³C NMR指纹图谱可作为鉴别金银花质量的依据.     

The 12C(18O, α)26Mg and 12C(18O, 8Be)22Ne reaction

Excitation functions for α-emission leading to the ground and first excited states of ²⁶Mg and ⁸Be emission leading to the ground and first and second excited states of ²²Ne have been measured at several forward angles for E_c.m. = 15 to 22.4 MeV. There is little evidence for correlated structure. The angular distribution at 16.5 MeV for the α + ²⁶Mg(g.s.) channel is rather structureless while that for the ⁸Be+²²Ne(g.s.) channel appears to be dominated by a J = 13 contribution. Statistical model calculations indicate that much of the yield for both the α and ⁸Be exit channel is compound nuclear in origin, with some indication of a larger direct contribution for the ⁸Be channel at the lower end of the bombarding energy range.     

13C high-resolution NMR study of doped polyacetylene

¹³C high resolution NMR spectra of doped trans polyacetylene, (CH)_x, have been measured. A spectrum of (CH)_x doped with AsF₅ shows a downfield shift, while that with potassium an upfield shift. The charge distribution and the existence of sp³ hybridized carbon on halogen-doped (CH)_x chains are discussed.     

Study of the reactions 12C(d,d)12C and 12C(d,p)13C across the resonance at Ed = 2.71 MeV

The second order processes in particle transfer reactions are tested by measuring the resonance structure of the 3⁺ state of ¹⁴N at 12.61 MeV for some outgoing channels of the ¹²C + d reaction.