Investigation of the local structure and the effects of the orbit reduction factor on the EPR g-factors for octahedral (CrO6) cluster in TiO2:Cr and MgO:Cr systems

A theoretical method for studying the inter-relation between electronic and molecular structure has been proposed based on the complete energy matrices for a d³ configuration ion in a tetragonal ligand-field. By means of this method, the local structure for Cr³⁺ ion doped in oxides TiO₂ (anatase) and MgO has been determined. The calculated results indicate that the local structure of the (CrO₆)⁹⁻ cluster in TiO₂:Cr³⁺ and MgO:Cr³⁺ systems exists as a compressed distortion relative to the regular octahedron. Meanwhile, the dependence of the EPR zero-field splitting parameter D on the local structure parameter ΔR (ΔR=R₁−R₂) has been revealed. In addition, the relation between the EPR g-factors (g,g,Δg) and the orbit reduction factor k has been discussed for the two systems, suggesting that the orbit reduction factor k is very important to understand the EPR g-factors.     

Synthesis, characterization and properties of β-octamolybdate-supported transition metal complexes with mixed ligands: [Cu(2,2′-bipy)(C6H5NO2)(H2O)]2[Mo8O26]·5H2O

A novel organic–inorganic hybrid compound [Cu(2,2′-bipy)(C₆H₅NO₂)(H₂O)]₂[Mo₈O₂₆]·5H₂O (1), (2,2′-bipy = 2,2′-bipyridine; C₆H₅NO₂ = pyridine-4-carboxylic acid) has been prepared and characterized by elemental analyses, IR spectrum, thermal stability analysis, and single-crystal X-ray diffraction. Compound 1 is a discrete cluster, constructed from β-[Mo₈O₂₆]⁴⁻ subunits covalently bonded to two [Cu(2,2′- bipy)(C₆H₅NO₂)(H₂O)]₂⁴⁺ coordination cations via terminal oxo groups that connect one molybdenum site. A 3D supramolecular network is further formed by extensive hydrogen bonding interactions and π–π interactions of the 2,2′-bipy and pyridine-4-carboxylic acid ligands. EPR and magnetic susceptibility studies have been used to elucidate the electronic properties of the Cu²⁺ centres, and the results are in good agreement with the structural features of the compound.     

Quinoline-3-carboxamide derivatives as potential cholesteryl ester transfer protein inhibitors

A series of novel quinoline-3-carboxamide derivatives 10-17 and 23-27 were designed and synthesized as cholesteryl ester transfer protein (CETP) inhibitors. All of them exhibited activity against CETP. Particularly, compounds 24 and 26 displayed the best activity against CETP with the same inhibitory rate of 80.1%.     

乙二胺盐酸盐的低温热容和热化学性质

合成了乙二胺盐酸盐, 并表征了其晶体结构. 测定了其在78~370 K温度区间的低温热容, 通过最小二乘法拟合得到热容对温度的多项式方程. 设计了合理的热化学循环, 测定了所设计反应的反应物和产物的溶解焓, 得到反应焓. 利用Hess定律计算出乙二胺盐酸盐的标准摩尔生成焓为-(540.74±1.33) kJ/mol. 利用紫外-可见光谱和折光指数的结果检验了所设计热化学循环的可靠性.     

异硫氰酸荧光素后修饰的金属有机三元环光解水制氢

将具有N、O、P三齿配位点的直线型双臂席夫碱配体L1与钴离子配位自组装得到一例[3+3]金属-有机三元环Co-L1。在该配体的苯环侧链上引入易于修饰的NH₂基团，通过组装后修饰的方法把光活性的异硫氰酸荧光素（FITC）分子以共价键方式键合到金属-有机三元环上，并将其用于可见光下的光解水制氢。该体系属于无须引入额外光敏剂的双组分放氢体系。与传统的三组分体系相比，在同等金属催化剂和光敏剂浓度下，组装后修饰的金属配合物催化剂Co-L3具有更高的光催化活性，转换数（TON）可以达到80，大约是Co-L1光催化效率的30倍。     

Rubiyunnanins A and B, two novel cyclic hexapeptides from Rubia yunnanensis

Two novel cyclic hexapeptides, named rubiyunnanins A (1) and B (2), were isolated from the roots of Rubia yunnanensis (Franch.) Diels. Their structures were elucidated extensively by spectroscopic analysis and theoretical computation. Possible biosynthetic pathways for RAs, 1, and 2 were proposed. Compound 2 showed moderate cytotoxicities against 11 cancer cell lines and inhibited nitric oxide (NO) production in LPS and IFN-γ-induced RAW 264.7 murine macrophages.     

微乳液成核-离子交联制备阿司匹林/壳聚糖纳米微球及其体外释放行为

以自制阿司匹林为药物模型,壳聚糖(CS)为载体源,采用微乳液成核-离子交联法制备了阿司匹林/壳聚糖纳米缓释微球.分别用傅里叶变换红外(FTIR)光谱、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、动态激光光散射(DLLS)、X射线粉末衍射(XRD)等表征了纳米微粒的化学组成、外观形貌、平均粒径和粒径分布、微球中壳聚糖的晶体结构以及阿司匹林的分布形态.结果表明,利用微乳液成核-离子交联法制备的阿司匹林/壳聚糖微球平均粒径约为88nm且粒径分布均匀,成核后壳聚糖结晶形态基本未变,阿司匹林以分子形态分布于微粒中,分子间未形成堆砌,为无定形态.采用UV-Vis分光光度计考察了微球的药物包封率、载药量,并对微球在生理盐水和葡萄糖溶液中的释药行为进行跟踪.结果表明,微球的载药量可达55%,药物包封率可达42%,实验条件下具有较好的药物缓释作用.     

离子化程度对硼取代富勒烯C19Bn+（n=0-3）体系储氢性能的影响

本文采用密度泛函理论方法,研究了氢气分子在硼取代富勒烯C19Bn+（n=0-3）表面的非解离吸附态、化学吸附态、及吸附态之间转换过渡态的结构和能量,得到了吸附态之间转换反应的势能面. 研究表明通过调整体系的离子化电荷可以调整吸附位点的电荷布居数,随着硼取代富勒烯离子化体系C19Bn+的吸氢活性位点电荷布居数增大,氢分子被极化的程度以及氢分子在材料表面的吸附能均逐渐增大,同时改变电荷布居数也对氢气分子在表面吸附态间转变势垒高度产生了量级为几个Kcal/mol的影响. 希望我们的研究能够对富勒烯储氢的进一步发展提供参考.     

在乙二醇溶液中合成复合金属醇盐和纳米NiFe2O4

在乙二醇溶液中用电化学法制备了镍、铁醇盐配合物NiFe2(OCH2CH2OH)8,将其溶液水解、真空干燥后在400℃煅烧2 h,得到纳米级NiFe2O4粉体.产物NiFe2(OCH2CH2OH)8通过红外光谱(FTIR)和拉曼光谱(Raman)进行表征,纳米NiFe2O4通过X射线粉末衍射(XRD)和电子显微镜(TEM、SEM)进行表征.实验表明,前驱体中含有OCH2CH2OH基团,可以有效克服水解与煅烧过程中的团聚现象,经400 ℃煅烧2 h得到的纳米NiFe2O4粉体,颗粒分散较好、纯度高,粒径在25～40 nm.     

[5-(芳亚甲基氨基)-1,3,4-噻二唑-2-基]硫乙酰芳胺的合成及 生物活性研究

在K2CO3存在下利用聚乙二醇-400 (PEG-400)作相转移催化剂, 于固-液相转移催化条件下, 通过5-芳亚甲基氨 基-2-巯基-1,3,4-噻二唑与氯乙酰芳胺的硫烷基化反应, 合成了16个未见文献报道的[5-(芳亚甲基氨基)-1,3,4-噻二唑-2-基]硫乙酰芳胺衍生物. 经元素分析, FT-IR,1H NMR和13C NMR确证了其结构. 生物活性实验结果表明, 部分化合物对小麦幼苗的生长具有明显的植物生长调节活性, 并对枯草杆菌具有一定的抑制活性.