花状Cu_2O/Cu复合材料的光催化性能

不采用任何模板,利用原位逐步水热方法一次性合成了花状Cu2O/Cu复合材料.采用X射线衍射、扫描电镜、高分辨透射电镜和自动吸附仪对样品的相结构、形貌和比表面积进行了表征.以偶氮染料Procion Red MX-5B为探针分子,对复合催化剂进行了可见光催化表征.结果表明该复合催化剂中的Cu和Cu2O之间存在相互作用,其催化活性远高于单相Cu2O和商用P25粉末,有望成为污水治理的新型材料.     

Synthesis and Crystal Structure of a Two-dimensional Cobalt Complex with 5-Tert-butyl Isophthalic Acid

The self-assembly of Co(OAc)·4H2O with H2tbip and bipy (H2tbip = 5-tert-butyl isophthalic acid, bipy = 4,4'-bipyridine) generates one new complex, [Co3(tbip)2(Htbip)2(bipy)]n, which has been characterized by elemental analysis, X-ray diffraction, and IR spectroscopy. Single-crystal X-ray analysis reveals that it crystallizes in the triclinic space group P1 with a = 9.471(6), b = 12.597(8), c = 12.899(8), α = 84.660(7), β = 70.548(7), γ = 81.965(7)o, V = 1435.1(15)3, Mr = 1215.85, Dc = 1.407 g/cm3, Z = 1, F(000) = 629, μ(MoKα) = 0.926 mm-1, the final R = 0.0623 and wR = 0.1724. The complex consists of a tbip bridged trinuclear cobalt() unit and is further linked by 4,4'-bipyridine molecule to form a 2D supramolecular network.     

A Three-dimensional Supramolecular Complex {[Co(H2btec)(2,2'-bipy)(H2O)3]·H2O}n Assembled via Hydrogen Bonding and π-π Stacking Interactions

A new cobalt compound, {[Co(H2btec)(2,2'-bipy)(H2O)3]·H2O}n (1, H4btec =1,2,4,5-benzenetetracarboxylic acid, 2,2'-bipy = 2,2'-bipyridine), has been synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR and X-ray powder diffraction. The crystal belongs to the triclinic system, space group P-1, with a = 7.230(3), b = 11.626(5), c =14.001(6) (A), α = 108.12(0)°, β= 95.85(0)°, V= 1095.33(157)(A)3, C20H20CoN2O12, Mr= 539.31,Z=2, Dc = 1.635 g/cm3,μ = 0.855 mm-1, F(000) = 554, R = 0.0427 and wR = 0.1042 for 3883 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). The title compound features a discrete molecular structure, which is connected with each other through extensive O-H…O hydrogen bonds into an intricate 3D supramolecular network. Additionally, two different patterns of π-π stacking interactions further consolidate the framework.     

5-氟胞嘧啶气相及水助质子转移异构化的理论研究

采用密度泛函B3LYP/6-311G**方法,对6种5-氟胞嘧啶异构体孤立分子的稳定性及质子转移引起的酮式-烯醇式、氨基式-亚胺式互变异构反应机理进行了计算研究,获得了零点能、吉布斯自由能及质子转移过程的反应焓、活化能、活化吉布斯自由能和速率常数等参数.计算结果表明,气相中烯醇-氨基式FC4是最稳定的异构体.分子内质子转移设计了FC1→FC2和FC1→FC6两条通道,分别标记为P(1)和P(2),各通道速控步骤的活化能和速率常数分别为155.9 kJ·mol-1,4.70×10-15 s-1和173.1 kJ·mol-1,1.41×10-18 s-1.水助催化时,相应通道P(3) 和P(4) 速控步骤的活化能和速率常数分别为51.0 kJ·mol-1,1.41×103 s-1和88.2 kJ·mol-1,4.53×10-3 s-1.可见,水分子的加入极大地降低了质子转移的活化能垒.另外发现,水分子参与形成协同的双质子转移机理比水助单质子转移机理更利于降低活化能垒.     

1-(2-萘基)-3-甲基-5-吡唑啉酮衍生试剂的制备及其在高效液相色谱-质谱法测定糖类化合物中的应用

以1-(2-萘基)-3-甲基-5-吡唑啉酮(NMP)作为柱前衍生试剂,建立了简单、灵敏的糖类组分的反相高效液相色谱测定方法。NMP与糖在氨为催化剂的条件下,于70 ℃下反应可获得稳定的衍生产物。在Hypersil ODS 2反相色谱柱上,实现了8种单糖的基线分离。衍生物线性相关系数均大于0.9985,检出限为0.58～1.1 pmol。利用柱后在线串联质谱的电喷雾电离正离子模式监测,获得了各组分的质谱定性及裂解规律,特别是m/z 473的特征碎片离子可作为单糖NMP衍生物的判定依据。与1-苯基-3-甲基-5-吡唑啉酮(PMP)相比,NMP对糖的衍生化具有灵敏、简单、质谱裂解规律性强、重现性好等优点。该方法用于测定油菜花粉多糖中的单糖组成,结果令人满意。     

四种5-氟尿嘧啶二肽衍生物的合成、晶体结构和抗癌活性

合成了四种新的5-氟尿嘧啶(5-Fu)二肽衍生物, 它们的结构经过元素分析、IR、1H NMR和13C NMR的表征, 比旋光度[a]D的测定结果表明了它们之间的对映异构关系, 用X射线衍射法测定了其中一对对映异构的晶体结构3a (S)和3b (R), 生物活性测试的结果表明这四种化合物都具有一定的抑制活性, 并且R型产物比S型产物抑制率高. 研究了2a和3a与DNA在Au电极上相互作用的伏安行为, 比较了它们跟5-氟尿嘧啶与双链DNA发生相互作用的差别.     

Cobalt(II) complexes with disubstituted 3-aminopyrazole derivative: Mononuclear Co(II) complex with in situ prepared formamidine ligand

In the reaction of Co(NO₃)₂ · 6H₂O with 4-acetyl-3-amino-5-methylpyrazole (aamp) two octahedral Co(II) complexes, [Co(aamp)₂(H₂O)₄](NO₃)₂, 1, and [Co(ampf)(MeOH)₂NO₃]NO₃ (ampf = N,N′-bis(4-acetyl-5-methylpyrazole-3-yl)formamidine), 2, were obtained, depending on the reaction conditions. The presence of water in the reaction system leads to incorporation of water molecules into the crystal lattice and 1 was formed. In an anhydrous environment, due to addition of CH(OEt)₃, the fusion of two aamp was induced through their NH₂-groups, incorporating the methine group of CH(OEt)₃. As a result, complex 2, containing an adenino-mimetic NNO pharmacophore ligand, was obtained. The crystal and molecular structure of both compounds was determined. The coordination of aamp in 1 was achieved through N2 of the pyrazole ring. On the contrary, in 2, an unusual coordination mode of pyrazole is found: one of the pyrazole moieties, due to steric hindrance, coordinates through the oxygen atom of the acetyl group instead of N2. The complexes were characterized by elemental analysis and electronic spectra. For 2 a comprehensive IR spectral analysis is given. The metal-ligand interactions in 2 are analyzed by quantum chemical computations. The desolvation mechanism of both compounds is discussed in detail.     

由5-磺基水杨酸组装的镧系金属有机骨架配合物的合成及结构

在水热条件下,合成了6个新的镧系金属配位聚合物,Ln₂(SSA)₂(phen)₄(H₂O)₂(Ln=Er(Ⅲ) (1),Yb(Ⅲ) (2)),[La₂(SSA)₂(phen)₂(H₂O)₄·(phen)·(H₂O)_{1.33相似文献}   

Effect of water on the performance of Pd-ZSM-5 catalysts for the combustion of methane

Palladium-based catalysts were prepared using impregnation （I） and ion-exchange method （E） with ZSM-5 as support. Pd-ZSM-5（I） and Pd-ZSM-5（E） catalysts presented the high activity for the combustion of methane. The order of activity was consistent with Brcnsted acidity of the catalysts： Pd-ZSM-5（I）〉Pd-ZSM-5（E）. It was shown by FT-IR that methane was adsorbed on the acidic bridging hydroxyl groups of ZSM-5-supported Pd catalysts. The effect of water on the activity of Pd-ZSM-5 was investigated. The inhibition effect of water on the conversion of methane was observed. However, water promoted the stability of Pd-ZSM-5 obviously during extended time periods. XPS measurement showed that Pd/Si ratio near the surface of Pd-ZSM-5（E） decreased more pronouncedly with time in dry stream than that of Pd-ZSM-5（I）, this is attributed to the dispersion of Pd into the micropores. The addition of water, however, retarded Pd dispersion. And high partial pressure of methane reduced this effect of water vapor. The decrease in activity during the stability test can be explained on the basis of the reduction of Pd/Si ratio.     

微波辐射下5-取代-2-硫代海因衍生物的合成

微波辐射下, 由硫氰酸铵与α-氨基酸通过两步反应合成了11种5-取代-2-硫代海因衍生物, 并用¹H NMR, IR和元素分析确证了中间产物和终产物的结构. 对比常规加热方法, 微波辐射具有反应时间短(4 min), 每步反应产率高(85%～93%)的优点. 同时对合成化合物2h的反应历程进行了讨论.