Automatic simulation of electrochemical transients by the adaptive Huber method for Volterra integral equations involving Kernel terms exp[?α(t ? τ)]erex{[β(t ? τ)]1/2} and exp[?α(t ? τ)]daw {[β(t ? τ)]1/2}

Development of fully automatic methods for the simulation of transient experiments in electroanalytical chemistry is a desirable element of the contemporary trends of laboratory automation in electrochemistry. In accord with this idea, the adaptive Huber method, elaborated by the present author, is intended to solve automatically integral equations of Volterra type, encountered in the theory of controlled-potential transients. The coefficients of the method have been recently obtained for integral transformation kernels involving terms K(t, τ) = exp[−α(t − τ)]erex{[β(t − τ)]^1/2} and K(t, τ) = exp[−α(t − τ)]daw{[β(t − τ)]^1/2} with α ≥ 0 and β ≥ 0, which are known to occur in the above integral equations. In this work the validity of the resulting method, for electrochemical simulations, is examined using representative examples of electroanalytical models involving integral equations with various special cases of such kernel terms. The performance of the method is found similar to that previously reported for integral equations involving exclusively kernels K(t, τ) = 1, K(t, τ) = (t − τ)^−1/2, and K(t, τ) = exp[−λ (t − τ)](t − τ)^−1/2 with λ > 0.     

α-酮酯和α-酮酰胺的Henry反应

用三乙胺催化环状α-酮酯和α-酮酰胺同硝基甲烷的Henry反应, 首次合成了12个多官能团的β-硝基醇, 它们的结构用元素分析、红外光谱和核磁共振进行了表征. 这一反应速度较快, 室温下进行, 条件温和, 产率较好, 是合成多官能团硝基醇的有效方法.     

水悬浮体系中α,β-环氧酮类化合物的合成研究

在水悬浮体系中使用三氯异氰尿酸/碱氧化体系对α,β-不饱和酮化合物进行环氧化和对烯丙基醇类化合物进行直接氧化-环氧化制备α,β-环氧酮, 考察了表面活性剂、碱等因素对反应的影响. 反应无需有机溶剂, 对于大部分的烯酮和烯丙基醇反应可以在数小时内完成, 产率良好.     

手性β-氨基醇催化α,β-不饱和酮的不对称环氧化反应

将以烯烃为原料通过Sharpless不对称双羟化等多步反应合成的8种手性β-氨基醇, 作为有机小分子催化剂, 用于催化α,β-不饱和酮的不对称环氧化反应．考察了影响对映选择性的催化剂结构、催化剂用量、氧化剂种类、溶剂、反应温度等因素．结果表明, 当催化剂用量为30 mol%、氧化剂为TBHP(叔丁基过氧化氢)、正己烷溶剂、在室温下、以(1S,2R)-(＋)-1,2-二苯基-2-甲氨基乙醇(3)作催化剂时, 所得环氧化物的对映体过量最高为70% ee, 产率最高为84%.     

MgCl2/Et3N催化合成α,β-不饱和氰代酯

用MgCl₂/Et₃N催化氰乙酸乙酯和芳香醛的缩合反应合成α,β-不饱和氰代酯, 反应可在室温进行. 产率87%～92%.     

微波辐射相转移催化下水相合成α,α'-双亚苄基环烷酮

芳醛与环戊酮或环己酮在碳酸钠水溶液中, 用微波辐射-相转移催化法合成 α,α'-双亚苄基环烷酮, 反应在0.5～7 min内完成, 产率高达80%～99%, 后处理极为简便, 是一种环境友好的绿色合成.     

Zn/AlCl3促进下二硫醚与α,β-不饱和化合物的共轭加成

二芳基二硫醚与锌粉在DMF 中110 ℃反应, 生成二硫醚与锌的复合物; 后者在无水AlCl₃存在下与丙烯酸酯、丙烯腈反应分别生成β-芳硫基丙酸酯和相应的腈, 产率48%～91%.     

In situ construction of ligand nano-network to integrin αvβ3 for angiogenesis inhibition

Angiogenesis occurs during the process of tumor growth, invasion and metastasis, and is essential for the survival of solid tumors. As an integrin significantly overexpressed in human tumor vascular endothelial cells, α_vβ₃ is a suitable targeting site for anti-angiogenesis of tumor. We designed and prepared a selfassembling peptide (SAP) with the ability to targeting α_vβ₃ and self-assembly. SAP formed nanoparticles in solution and transformed into nanofibrous network once specifically binding to integrin α_vβ₃ on the surface of human umbilical vein endothelial cells (HUVECs). The SAP network stably anchored on HUVECs over 24 h, which consequently resulted in high-efficient inhibition of vascularization. In vitro anti-angiogenesis experiment displayed that the inhibition rate of tube-formation reached 94.9%. In vivo anti-angiogenesis array based on chick chorioallantoic membrane (CAM) model exhibited that the SAP had an inhibition rate up to 63.1%. These results indicated the outstanding anti-angiogenic ability of SAP, potentially for tumor therapy.     

基于π…π和C-H…π作用力构筑的磺酰腙镍(Ⅱ)配合物的超分子组装

在温和条件下,以对甲苯磺酰氯为初始原料合成了具有新颖Ni-O(磺酰基)配键的磺酰腙镍(Ⅱ)配合物NiL₂(HL:4-甲基-N'-(吡啶-2-亚甲基)苯磺酰肼)。晶体结构研究表明,该配合物仅通过π…π和C-H…π作用组装成两种不同类型的二聚体,一是通过平行四重芳基环绕(P4AE：由面对面(OFF)和边对面(EF)π堆积组成)相互作用组装而成,二是仅通过OFF相互作用进行组装。沿着c轴方向,两类二聚体通过P4AE和OFF作用的组合,以“头碰头”形式组装成一维链。每个二聚体均包含了两种不同的对映体形式。利用B3LYP/6-31++G^**方法,对两种二聚体结构单元单点能计算表明,具有P4AE作用的二聚体存在着OFF和EF的协同作用,也印证和和支持了实验结果。光谱研究确证溶液中Ni(Ⅱ)和HL形成了物质的量之比为1∶2配合物。     

11β-羟基-16β-甲基-16α,17α-环丙烷基-孕甾-1,4-二烯-3,20-二酮的合成

由泼尼松龙(Prednisolone)为原料, 经甲磺酰化、甲基化、脱水、两次1,3-偶极反应以及其后的两次热分解共7步反应, 以23.5%的总收率首次制得了11β-羟基-16β-甲基-16α,17α-环丙烷基-孕甾-1,4-二烯-3,20-二酮这一重要的潜在药物及化学中间体. 实验同时发现, 1,3-偶极反应及其之后的热分解反应具有高度的立体选择性和区域选择性. 这种立体选择性和区域选择性通过¹H NMR数据加以了证明.     

Hydrodeoxygenation of Anisole over Ni/α-Al2O3 Catalyst

Ni-based catalysts supported on di erent supports (α-Al₂O₃,γ-Al₂O₃, SiO2, TiO₂, and ZrO₂) were prepared by impregnation. Effects of supports on catalytic performance were tested using hydrodeoxygenation reaction (HDO) of anisole as model reaction. Ni/α-Al₂O₃ was found to be the highest active catalyst for HDO of anisole. Under the optimal conditions, the anisole conversion is 93.25% and the hydrocarbon yield is 90.47%. Catalyst characteriza-tion using H₂-TPD method demonstrates that Ni/α-Al₂O₃ catalyst possesses more amount of active metal Ni than those of other investigated catalysts, which can enhance the cat-alytic activity for hydrogenation. Furthermore, it is found that the Ni/α-Al₂O₃ catalyst has excellent repeatability, and the carbon deposited on the surface of catalyst is negligible.     

α-糜蛋白酶催化合成β-脲基巴豆酸酯

β-脲基巴豆酸酯是合成6-甲基嘧啶二酮衍生物及3,4-二氢嘧啶二酮衍生物的重要中间体,在生物制药中有着广泛的应用.由于酶具有绿色、安全、高效的催化特性,采用α-糜蛋白酶为生物催化剂,以N,N-二甲基甲酰胺为反应介质,37℃条件下,通过1,3-二羰基化合物和脲的缩合反应,合成了一系列β-脲基巴豆酸酯类化合物.     

水介质中α,α-双(4-羟基香豆素-3-基)甲苯的洁净合成

在水介质中三乙基苄基氯化铵(TEBA)存在下, 芳醛与4-羟基香豆素反应为α,α-双(4-羟基香豆素-3-基)甲苯提供了一种快速、方便、高效和洁净的合成方法.     

水峰调制下的3,4-Seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic Acid的NMR结构解析

对海南半红树植物黄槿(Hibiscus tiliaceus)内生菌中提取的一个新化合物进行核磁共振结构解析的研究. 在核磁共振测试时发现水峰信号与部分样品信号发生了重叠, 直接影响了该化合物谱图数据的分析. 本工作通过实验确证了在氘代二甲亚砜(DMSO-d₆)溶剂中水峰化学位移与含水量之间的变化规律. 依据该规律, 利用定量加入纯水的方法对实际样品中的水峰信号进行了调制, 解决了水峰信号与样品信号的重叠问题, 得到了较理想的¹H NMR, ¹³C NMR一维谱和COSY, HMQC, HMBC等二维谱. 利用核磁共振提供的信息完成了对新化合物结构的解析, 确定该化合物为齐墩果烷三萜类化合物3,4-seco-olean-11,13-dien-4,15α,22β,24-tetraol-3-oic acid.     

CsCl/NH4 β沸石固态离子交换过程

采用XRD和TG-DTA技术考察了NH₄ β沸石和CsCl的固态离子交换过程，并用吡啶-IR和异丙醇分解反应研究了Cs β沸石的酸碱性质。结果显示Cs⁺离子易以极高离子交换度引入β沸石，由固态离子交换得到的Cs β具有更高的碱催化脱氢能力。     

Synthesis and characterization of dinuclear p-, m- and o-xylyl bridged complexes of molybdenum and tungsten. The crystal structures of μ-p-xylyl- bis(η-pentamethyl-cyclopentadienyltri- carbonylmolybdenum) and μ-m-xylyl-bis(η- pentamethylcyclopentadienyltricarbonyltungsten)

The reactions of (M = Mo, W) with α,α′-p-, m- and o-dichloro-xylenes yielded p-, m- and o-xylyl bridged dinuclear complexes of in high yields. All of such new complexes are stable to air and water, even stable in dilute acids and bases.     

1-取代胺甲基-7,8-二去氢-4-羟基-3,7-二甲氧基-17-甲基-9α,13α,14α-吗啡烷-6-酮的合成

超声波辐射下, 以盐酸青藤碱为原料, 在其A环1-位碳上进行Mannich反应, 合成了2个新的取代胺甲基化合物 1a, 1b. 且由化合物1a与取代芳胺及吗啉通过胺交换反应合成了8个新的取代胺甲基化合物2a～2h. 所有新化合物的结构利用IR, MS, ¹H NMR及NOE差谱进行了表征.     

La0.8Sr0.2Ga0.8Mg0.2O3－α陶瓷的质子导电性能研究

采用溶胶-凝胶法合成了La_0.8Sr_0.2Ga_0.8Mg_0.2O_3－a陶瓷样品, 用XRD, DSC-TGA, SEM, 交流阻抗谱, 气体浓差电池及气体电化学透过等方法对样品的结构和性质进行了表征和测试. 首次对该样品的质子导电性能进行了研究. 该陶瓷样品具有良好的微观结构, 相对密度达95.1%; 氢浓差电池电动势的实测值与理论值吻合, 离子迁移数为1; 在干燥的氧气气氛中是一个纯的氧离子导体; 氢的电化学透过速率的实测值与理论值吻合, 证明该样品在氢气气氛中几乎是一个纯的质子导体, 质子电导率在1000 ℃时高达0.14 S•cm^－1.     

Modeling Ar and Kr matrix effect on the ν s (Cl–H) and ν l (Cl–H) of Cl–H···NH3 by the IEF-PCM method

Ar and Kr matrix effect on the geometry and Cl–H stretching (ν _s (Cl–H)) and librational (ν _l (Cl–H)) frequencies of the hydrogen-bonded complex Cl–H···NH₃ are simulated within the framework of polarizable continuum model with integral equation formalism (IEF-PCM) at B3LYP and MP2 levels of theory with the basis set 6-311++G(2df,2pd). Within the framework of B3LYP and IEF-PCM, the simulated gas phase, Ar, and Kr matrix ν _s (Cl–H) of the complex are 2140, 1684, and 1550 cm⁻¹, respectively, which deviate from the experimental values (~2200, 1371, and 1218 cm⁻¹) by −60, 313, and 332 cm⁻¹. Within the framework of MP2 and IEF-PCM, the gas phase, Ar, and Kr matrix ν _s (Cl–H) are calculated as 2366, 2037, and 1957 cm⁻¹ by the harmonic approximation, and as 2177, 1876, and 1665 cm⁻¹ by the full-dimensional anharmonic correction. The matrix effect modeling is of greater importance than the anharmonic correction in accounting for the large experimental gas phase to Ar or Kr matrix shift of the ν _s (Cl–H) (−829 or −982 cm⁻¹). Our calculations do not support the assignment of the 733.8 and 736.9 cm⁻¹ bands to the Ar and Kr matrix ν _l (Cl–H).     

层状化合物α-磷酸锆的制备和表征

用直接沉淀法，采用玻璃反应瓶，在常温常压条件下制备α-磷酸锆(α-ZrP)，并采用XRD、IR、SEM、TPDE和DG-DTA等方法对其进行了表征。结果表明α-磷酸锆的结晶度较高，层间距7.66A。晶体结构中有-HPO₄基团存在，含有一种结晶水，-HPO₄基团中的羟基与结晶水以氢键相连。其晶体平均粒径约2 μm，呈薄片状。α-ZrP晶体的结晶水在90～200℃之间被脱除，层板羟基在200℃开始缓慢脱除，到6