Structure and order of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene as revealed by diffraction and molecular simulation studies

The aggregate structure of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene (HPT) was studied both for the crystalline state and the liquid crystalline state by using electron crystallography and a molecular simulation approach. In the crystalline state, HPT was found to adopt an orthorhombic P-2212 space group with cell parameters a = 36.73 Angstrom, b = 27.99 Angstrom and c = 4.91 Angstrom. Molecular packing calculations were conducted to elucidate the molecular conformation and mutual orientational characteristics in the different states. Phase transitions and relationships are discussed from a structural point of view.

Complete assignment of H-1-NMR resonances of the king cobra neurotoxin CM-11

The king cobra(Ophiophagus hannah) neurotoxin CM-11 is long-chain peptide with 72 amino acid residues. Its complete assignment of H-1-NMR resonances was obtained using various 2D-NMR technologies, including DQF-COSY, clean-TOCSY and NOESY.

Determination of the secondary structure of the king cobra neurotoxin CM-11

The king cobra neuotoxin CM-11 is a small protein with 72 amino acid residues. After its complete assignments of H-1-NMR resonance's were obtained using various 2D-NMR technologies, including of DQF-COSY, clean-TOCSY AND NOESY, the secondary structure was analysed by studying the various NOEs extracted from the NOESY spectra and the distribution of chemical shifts. The secondary structure was finally determined by MCD as follows: a triple-strand antiparallel beta sheet with I20-W36, R37-A43 and V53--S59 as its beta strands, a short alpha helix formed by W30-G35 and four turns formed by P7-K10, C14-G17, K50-V53 and D61-N64.

Tb(111) and Ca(11) ion equilibria in the presence of glutamic acid and glutamine

Tb(111) and Ca(11) ion equilibria in the Presence of glutamic acid and glutamine were studied by potentiometric titration at 37 degrees C and an ionic strength of 0.15mol/L(NaCl). The stability constants for Tb(111) and Ca(11) complexes in the systems were obtained. The species and their distribution in the systems were discussed.

眼镜王蛇神经毒素CM-11核磁共振氢谱谱峰的完全归属

眼镜王蛇抽提物ＣＭ－１１为含７２个残基的长链神经毒素，对其进行了ＤＱＦ－ＣＯＳＹ，ＴＯＣＳＹ和ＮＯＥＳＹ等一系列２Ｄ－ＮＭＲ谱测定，借助序列专一归属法完成了ＣＭ－１１ＮＭＲ氢谱的完整归属。

眼镜王蛇蛇毒神经毒素CM-11二级结构单元的判定

眼镜王蛇毒液抽提物ＣＭ－１１为含７２个残基的长链神经毒素，对其进行了ＤＱＦ－ＣＯＳＹ，ＴＯＣＳＹ和ＮＯＥＳＹ等一系列２Ｄ－ＮＭＲ谱测定，通过系统地分析各种ＮＯＥ信息、化学位移的分布等数据推测了蛋白质有规律二级结构，最后利用ＭＣＤ主链引导法确定了它的二级结构。其中有三段反平行β折叠股（Ｉ２０～Ｗ２６、Ｒ３７～Ａ４３和Ｖ５３～Ｓ５９）、一段α螺旋构象（Ｗ３０～Ｇ３５）和四个可能的转角（Ｐ７～Ｋ１０，Ｃ１４～Ｇ１７，Ｋ５０～Ｖ５３，Ｄ６１～Ｎ６４），蛇毒神经毒素ＣＭ－１１其他肽片段处在伸展构象。

新型层柱微孔材料──FeW_（11）NiO_（39）柱撑ZnAl阴离子粘土的合成、表征及催化性能

采用水热合成与离子交换方法，将中心原子为过渡金属（Ｆｅ）的钨系过渡金属取代型杂多阴离子ＦｅＷ_（１１）ＮｉＯ_（３９）（Ｈ_２Ｏ）￣（７－）（缩写为ＦｅＷ_（１１）Ｎｉ）嵌入ＺｎＡｌ型阴离子层状结构粘土间，获得了大层间距、通道高度达１．３２ｎｍ的新型层柱微孔化合物。通过ＸＲＤ、ＩＲ及ＥＳＲ等手段进行了表征。以ＺｎＡｌ－Ｆｅｗ_（１１）Ｎｉ为催化剂合成邻苯二甲酸二辛酯（ＤＯＰ），选择性大于９９％，转化率由嵌入前的１２％提高到近５０％，催化活性明显提高。

IN-SITU SCANNING-TUNNELING-MICROSCOPY IMAGE OF A HIGHLY ORIENTED PYROLYTIC-GRAPHITE ELECTRODE MODIFIED WITH POTASSIUM BIS(11-MOLYBDOSILICATO) DYSPROSATE(III) IN SODIUM-SULFATE SOLUTION

The variation in molecule adsorption mode on pretreated highly oriented pyrolytic graphite electrodes, modified with the title complex K10H3[Dy(SiMo11O39)(2)] by cyclic voltammetry in the title complex solution, was observed in situ by electrochemical scanning tunnelling microscopy (ECSTM) with molecular resolution in sodium sulphate solution. According to the ECSTM images and the known molecular structure we conclude that the adsorption mode of the title complex modified electrode changed during potential cycling from ''vertical'' to ''inclined'' and then ''horizontal'' or ''flat'' mode, i.e. the title complex adsorbed on the surface of electrode by one ligand of the complex at first, then began to incline and was finally adsorbed by two ligands of the complex. This result indicates that the adsorption mode on the modified electrode surface changed during potential cycling in the sulphate solution and a much more stable molecular layer was formed. The change in adlattice of adsorbates on the modified electrode surface from hexagonal to rectangular was also observed by ECSTM. A plausible model was given to explain this process.

Electrochemical Study of the Transfer of Bis-1:11 Molybdosilicate Heteropolyanion with Dysprosium across the Liquid/Liquid Interface

The transfer of bis-1:11 molybdosilicate heteropolyanion with dysprosium across the water/nitrobenzene interface has been investigated by chronopotentiometry with linear current scanning and cyclic voltammetry. The strandard transfer potential and Gibbs energy estimated from cyclic voltammetry were 0.102V and -39.5kJ.mol(-1), respectively. The kinetic parameters of the transfer were determinated by chronopotentiometry with the linear current scanning.

双1:11镝的硅钼杂多酸的液/液界面电化学研究

用循环线性电流扫描计时电位法和循环伏安法研究了双1∶11镝的硅钼杂多酸阴离子在水／硝基苯界面的转移。在pH＝1．1～5．3时，转移离子为H9Dy（SiMo11O39）24－．根据循环伏安结果计算得转移离子的标准电位差和Gibbs转移自由能分别为0．102V和－39．5kJ·ml-1，并由循环线性电流扫描计时电位法计算了转移离子的有关动力学参数，H9Dy（SiMo11O39）24-在水／硝基苯界面的转移属准可逆转移.

一种对异戊二烯立体控制聚合较敏感的稀土催化体系

发现了一种对异戊二烯聚合立体选择性较敏感的稀士催化体系：（β－ＣＨ＿３－ａｌｌｙｌ）＿２ＬｎＣｌ＿５Ｍｇ·２Ｔ的ＥＤ（Ｌｎ）－Ｒ＿３Ａｌ（Ａｌ）（Ｌｎ＝Ｎｄ、Ｃｅ和Ｌａ，Ｔ的ＥＤ：Ｎ，Ｎ，Ｎ′，Ｎ′－四甲基乙二胺；Ｒ＝Ｍｅ一，Ｅｔ一，ｉ－Ｂｕ一和Ｏｃｔ一）．该催化体系在改变聚合温度、聚合时间、Ａｌ／Ｌｎ摩尔比、溶剂等时，可使聚异戊二烯的立体现整度有较大的改变，其中顺式－１，４、反式－１，４和３，４－链节含量的变化范围分别为１９％～７９％、１７％～７８％和０％～３．５％，还可获得较低分子量的聚合物。

脂肪二胺对热致液晶聚酯酰亚胺热行为的影响

用差示扫描量热法和热重法研究了热致液晶聚酯酰亚胺（ＰＥＩ）中己二胺（Ｃ６）、戊二胺（Ｃ５）以及癸二胺（Ｃ１０）组成对ＰＥＩ的相转变温度、玻璃化转变温度（Ｔｇ）和热稳定性的影响。

镧系元素钼系双11系列杂多蓝的离析和性质研究

本文首次报道了镧系元素钼系双11系列两电子杂多蓝K_yH_z[Ln(XMo_(11)O_(39)_2]·nH_2O(X=P,Ln=La、Ce、Pr、Nd、Sm、Gd;X=Si,Ln=Ce、Pr、Sm、Tb、Dy;X=Ge、Ln=Dy)的制备和离析方法.并通过元素分析、红外光谱、可见-紫外光谱、极谱、循环伏安、热分析、ESR、~(31)P NMR、XPS对产物进行了表征及性质研究.结果表明:杂多蓝阴离子结构较之还原前发生了轻微畸变,还原电子具有一定的离域性.在溶液中杂多蓝较还原前的杂多酸(盐)具有略强的氧化能力.溶液中杂多蓝的氧化能力Ln-P(2)>Ln-Si(2).热稳定性Ln-P(2)>Ln-Si(2).该系列杂多蓝还具有较好的抗碱解能力.

氯化镱与α-脯氨酸配合物的合成及结构研究

在水溶液中合成了氯化镱与α-脯氨酸(Pro)的配合物,研究了配合物的红外光谱。X射线衍射测定结果表明,其结构式为{[Yb(Pro)_2(H_2O)]Cl_3}_n,属单斜晶系,空间群P_(21),晶胞参数为:a=0.8268(1)nm,b=1.0980(3)nm,c=1.1965(4)nm,β=106.97(2)°,V=1.04120(5)nm~3,Z=2。每两个镱原子之间通过一个脯氨酸的羧基桥相连而形成一维链式聚合物,另一脯氨酸羧基以单齿形式与镱原子配位。镱的配位数为8,配位多面体为三角十二面体。