异腈参与的多组分反应研究进展

多组分反应由于反应本身的经济性和生态价值,越来越受到人们的重视。异腈的亲电和亲核反应均发生在碳原子上,因此在多组分反应中具有重要作用。本文就近年来有异腈参与的多组分反应进行了综述,主要阐述了Ugi反应和Passerini反应及其他含异腈参与的多组分反应的机理、研究开展及应用情况。     

Phebalosin的全合成

以间苯二酚和D,L-苹果酸为原料,经Pechmann反应、Reimer-Tiemann反应、Darzens缩合反应及Wittig反应合成了Phebalosin,总收率1.3%,其结构经~1H NMR和~(13)C NMR表征.     

温度和时间对有机合成反应影响的探讨

根据物理化学和有机合成原理,从动力学、热力学、反应机理及溶解度等各方面详细分析了反应温度和反应时间对有机合成反应的影响。通过这些分析,可以让同学们更好地在合成反应课程的学习中掌握和分析反应温度和反应时间对反应的影响。     

反应类等键反应方法及类反应热动力学参数计算

本文提出了反应类等键反应方法,将通常用于热力学性质计算的等键反应方法推广用于类反应中反应势垒和反应焓变的计算. 对碳氢燃料低温燃烧反应机理中的一类重要反应类：?烷基自由基过氧化氢裂解生成烯烃和HO2自由基的反应势垒和反应焓变进行了计算. 通过对该类16个反应中的5个代表反应分别在不同计算水平HF、DFT、MP2、CCSD(T)的比较计算发现,采用等键反应方法可在较低从头算级别计算得到类反应较高精度的反应势垒,提高了计算的效率和精度. 本文采用反应类等键反应方法在B3LYP/6-311G(d,p)计算水平对该类16个反应进行了反应势垒和反应焓变的计算,并建立了反应势垒和反应能的线性自由能关系：delta V=71.02+0.41?delta E.     

芳香取代反应—ipso取代反应

谈到芳香取代反应,人们立刻会想到芳环上取代基的o~-、p-、m~-位上氢原子的取代反应。然而对另一类反应,即环上取代基本身的取代反应却少为人知。它是起始于试剂对芳环上取代基所在位置(ipso位)的进攻,进而置换了该取代基的反应。称作ipso取代反应。某些研究表明,试剂对氢原子所在位置的进攻与它对ipso位的进攻处于竞争状态,往     

有机锑化合物在交叉偶联反应中的应用研究进展

近年来,有机锑化合物在交叉偶联反应中的应用引起了人们的广泛关注。本文主要对有机锑化合物在交叉偶联反应中的应用作了综述,重点介绍了其在Suzuki交叉偶联反应、Heck偶联反应以及Sonogashira偶联反应中的应用,并展望了其未来的发展方向。     

过氧烷基自由基分子内氢迁移反应类速率常数的计算

过氧烷基自由基分子内氢迁移是低温燃烧反应中的一类重要基元反应. 本文用等键反应方法计算了该类反应的动力学参数. 所有反应物、过渡态、产物的几何结构均在B3LYP/6-311+G(d,p)水平下优化得到. 本文提出了用过渡态反应中心几何结构守恒作为反应类判据, 并将该分子内氢迁移反应分为四类, 包括(1,3)、(1,4)、(1,5)、(1,n) (n=6, 7, 8)氢迁移类. 分别将这4 类反应类中最小反应体系作为类反应的主反应, 并分别在B3LYP/6-311+G(d,p)低水平和CBS-QB3 高水平下得到其近似能垒和精确能垒. 其余氢迁移反应作为目标反应, 在B3LYP/6-311+G(d,p)低水下计算得到其近似能垒, 再采用等键反应方法校正得到目标反应的精确反应势垒和精确速率常数. 研究表明, 采用等键反应方法只需在低水平用从头算计算就可以得到大分子反应体系的高精度能垒和速率常数值, 且本文按等键反应本质的分类方法更能揭示反应类的本质, 并对反应类的定义给出了客观标准. 本文的研究为碳氢化合物低温燃烧模拟中重要的过氧烷基分子内氢迁移反应提供了准确的动力学参数.     

丙二腈在多组分反应中的应用*

丙二腈分子中的氰基作为强吸电子基团活化亚甲基,也是良好的离去基团,以及氰基的碳氮三键可进行加成反应,使得丙二腈是一种非常特别的化合物。它具有非常丰富的反应性质,可以发生Knoevenagel缩合、Michael加成、环化和消去等反应,是进行多组分合成反应的优良试剂。由其参加的多组分合成反应已经成为合成众多碳环和杂环化合物的重要方法。本文综述了丙二腈在多组分反应中的研究进展,介绍了近年来丙二腈参加的多组分反应合成环状化合物的成功事例,展望了丙二腈反应的发展方向。     

有机反应的竞争性

有机反应的竞争性胡秀贞（南京师范大学化学系，２１００２４）竞争反应是有机化学中一个相当普遍的反应，所以我们研究有机反应机理时，必须具有有关这个反应的热力学和动力学的基本知识。大家知道热力学研究的一个重要内容是反应的起始状态和终止状态的能量变化，而动力...     

钯催化合成嘧啶核苷衍生物的研究进展

嘧啶核苷衍生物在药物化学、生物探针和核酸化学的研究中具有重要的作用, 金属催化碳碳的形成广泛应用于嘧啶核苷衍生物的合成. 综述了钯催化的Sonogashira反应、Stille反应、Heck反应以及Hiyama反应在嘧啶类核苷衍生物合成中的应用.     

仪器与设备自动化管理系统方案

结合仪器与设备的管理现状，提出了仪器、设备自动化管理系统软件开发的整体思路。介绍了软件中的建立档案、查询资料、修改档案、打印报表、更新资料、作废仪器与设备目录、帮助、退出8个子系统的功能。     

电感耦合等离子体原子发射光谱分析信息系统的开发 Ⅰ.系统分析

根据电感耦合等离子体原子发射光谱（ＩＣＰ－ＡＥＳ）分析的实际需要，开发了一种 ＩＣＰ－ＡＥＳ分析信息系统。该系统包括谱线管理系统、识别干扰程度系统、校准及干扰校正系 统、帮助系统等子系统。本文将讨论系统分析。系统设计和系统评价将在另文中讨论。     

分子动力学模拟研究纳米碳管中甲醇-水混合溶液的结构与输运性质

利用分子动力学模拟方法,对比考察了平衡条件、外压作用、梯度电场作用下,摩尔比为1:1的甲醇-水混合溶液在纳米碳管(CNT)中的静态结构以及输运行为.研究发现:在平衡体系与外压作用下,纳米碳管内甲醇与水呈现出明显的不混溶现象,甲醇主要分布于管壁附近,水分子主要分布于纳米碳管轴心附近;而在梯度电场作用下,纳米碳管由疏水性向亲水性转变,更多的水分子分布于管壁,导致纳米碳管内甲醇-水的不混溶现象消失.另一方面,在外压作用下,纳米碳管内甲醇与水呈现单向移动;而在梯度电场下,甲醇与水呈现快速的双向移动,其流通量较相应外压作用体系高出近一个数量级,但由于双向的流通量大小相近,导致净流通量与外压作用下的净流通量差异不大.     

分子动力学模拟研究纳米碳管中甲醇-水混合溶液的结构与输运性质

利用分子动力学模拟方法,对比考察了平衡条件、外压作用、梯度电场作用下,摩尔比为1：1 的甲醇-水混合溶液在纳米碳管（CNT）中的静态结构以及输运行为. 研究发现：在平衡体系与外压作用下,纳米碳管内甲醇与水呈现出明显的不混溶现象,甲醇主要分布于管壁附近,水分子主要分布于纳米碳管轴心附近;而在梯度电场作用下,纳米碳管由疏水性向亲水性转变,更多的水分子分布于管壁,导致纳米碳管内甲醇-水的不混溶现象消失. 另一方面,在外压作用下,纳米碳管内甲醇与水呈现单向移动;而在梯度电场下,甲醇与水呈现快速的双向移动,其流通量较相应外压作用体系高出近一个数量级,但由于双向的流通量大小相近,导致净流通量与外压作用下的净流通量差异不大.     

System zones in capillary zone electrophoresis

When working with capillary zone electrophoresis (CZE), the analyst has to be aware that the separation system is not homogeneous anymore as soon as a sample is brought into the background electrolyte (BGE). Upon injection, the analyte creates a disturbance in the concentration of the BGE, and the system retains a kind of memory for this inhomogeneity, which is propagated with time and leads to so-called system zones (or system eigenzones) migrating in an electric field with a certain eigenmobility. If recordable by the detector, they appear in the electropherogram as system peaks (or system eigenpeaks). However, although their appearance can not be forecasted and explained easily, they are inherent for the separation system. The progress in the theory of electromigration (accompanied by development of computer software) allows to treat the phenomenon of system zones and system peaks now also in very complex BGE systems, consisting of several multivalent weak electrolytes, and at all pH ranges. It also allows to predict the existence of BGEs having no stationary injection zone (or water zone, EO zone, gap, dip). Our paper reviews the theoretical background of the origin of the system zones (system peaks, system eigenpeaks), discusses the validity of the Kohlrausch regulating function, and gives practical hints for preparing BGEs with good separation ability not deteriorated by the occurrence of system peaks and by excessive peak-broadening.     

On-line monitoring of granule growth in high shear granulation by an image processing system

A novel system has been developed to continuously monitor granule growth in a high shear granulation. The system consists of an image processing system and a particle image probe comprising a CCD camera, lighting unit and air purge system. Segregation during powder mixing was investigated experimentally and the optimal positioning of the probe was determined. High shear granulation was conducted using pharmaceutical powders, and granule size and product's yield of various size ranges were continuously measured by the developed system. Sieve analysis of the granulated products sampled out during the granulation was simultaneously conducted, and the obtained data was compared with that by the on-line image processing system. An extremely close relationship could be found between both data, proving that the developed system could monitor the granule growth accurately and continuously throughout the granulation. An on-off control system was developed to control the granulation process, and the performance of the system was confirmed.     

地塞米松磷酸钠的流动注射-化学发光分析法的研究

实验了地塞米松磷酸钠在K3Fe（CN）6-鲁米诺、KMnO4-鲁米诺、KIO4-鲁米诺、H2O2-鲁米诺体系中的化学发光现象。结果表明,地塞米松磷酸钠能够显著增强K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系的化学发光强度,而在另外两个体系中没有增强作用。结合流动注射技术,分别在K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系中建立了测定地塞米松的新方法。方法的线性范围分别为1.0×10^-7-1.0×10^-5g/mL和6.0×10^-8-1.0×10^-5g/mL,检出限分别为3.0×10^-8g/mL和2.0×10^-8g/mL,相对标准偏差分别为1.6%和1.9%（1.0×10^-6g/mL地塞米松,n=11）。此法已用于针剂和片剂样品的测定,结果与药典方法没有显著性差异。     

Chemical Equations for Multireaction Systems

While the balanced chemical equations for a multireaction system are generally not unique, the minimum number of independent equations, R, is a characteristic property of the system. Deleting one nonspectator species from the system leads to a system with R reduced by one. In this way each system can be reduced to a single-reaction system and ultimately to a no-reaction system. The least number of chemical species that can be deleted to obtain a no-reaction system equals R. Every multireaction system, therefore, can be reduced to a number of single-reaction equations which can be balanced by any one of the standard techniques. Some examples are given where balancing by inspection is employed.     

自催化三分子模型内噪声随机共振

The stochastic resonance in chemical reaction systems has recently attracted growing attentions. Using chemical Langevin equation,the effect of internal noise has been studied on the dynamical behavior of a single and a one-way coupled cubic autocatalator. For the single system,it is found that the internal noise can induce sustained oscillations,and the signal-to-noise ratio（SNR）undergoes a maximum with the variation of the system size. For the coupled system,the SNR passes through a maximum with changing coupling strengths as well as with changing system sizes,which demonstrates the occurrence of the internal noise stochastic resonance（INSR）and optimal size effect. In the presence or absence of influx into the system,the coupling enhanced or suppressed INSR is found in the coupled system. All cells of the coupled system appear to exhibit INSR at an approximately equal size at a suitable coupling strength,implying that the optimal system size and coupling strength can make the system reach an optimal chemical reaction state.     

A palmtop-sized microfluidic cell culture system driven by a miniaturized infusion pump

A palmtop-sized microfluidic cell culture system is presented. The system consists of a microfluidic device and a miniaturized infusion pump that possesses a reservoir of culture medium, an electrical control circuit, and an internal battery. The footprint of the system was downsized to 87 × 57 mm, which is, to the best of our knowledge, the smallest integrated cell culture system. Immortalized human microvascular endothelial cells (HMEC-1) and human umbilical vein endothelial cells (HUVEC) were cultured in the system. HMEC-1 in the system proliferated at the same speed as cells in a microchannel perfused by a syringe pump and cells in a culture flask. HUVEC in the system oriented along the direction of the fluid flow. Claudin-5, a tight junction protein, was localized along the peripheries of the HUVEC. We expect that the present system is applicable to various cell types as a stand-alone and easy-to-use system for microfluidic bioanalysis.