聚苯乙烯负载2-氨基-5-甲硫基-1,3,4-噻二唑螯合树脂的合成及吸附性能

杂环功能是一类对过渡金属离子、尤其是贵金属离子具有良好的吸附性能的功能基,它能利用环中的杂原子与金属离子形成稳定的多齿配合物,因此,含杂环功能基的螯合树脂,在分析、冶金、水处理、海洋资源利用等领域有广泛的应用价值[1-2]。目前文献报道较多的是将含硫、氮配位原子的     

2-氧代-2-(2-氯-5-吡啶甲氨基)4-取代苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷的合成

新烟碱类杀虫剂是人们对天然烟碱研究开发的一类超高效杀虫剂,是烟碱乙酰胆碱受体(nAchR)的效应剂,具有活性高,广谱杀虫,对对抗性昆虫有良好的防效,并且对哺乳动物毒性低.人们对该类杀虫剂的构效关系研究表明:活性化合物均具有3-氨甲基吡啶结构单元,氮原子上连有强吸电子基,氮原子带有部分正电荷.1,3,2-二氧磷杂环以其广泛的生物活性使其成为农药、医药合成中的重要活性结构单元.     

3-苯氧基甲基-4-(4-甲基苯基)-5-(2-吡啶基)-1,2,4-三唑的铜(Ⅱ)、镉(Ⅱ)配合物的合成、晶体结构和光学性质

以3-苯氧基甲基-4-(4-甲基苯基)-5-(2-吡啶基)-1,2,4-三唑(L)为配体分别合成了2个金属配合物即[Cu2L2Cl4]·2H2O(1)和[Cd3L2(μ2-Cl)6]n·2n CH3CN(2),对其进行了红外、紫外、热重、粉末衍射、元素分析和晶体结构等表征。配合物1和2都属于三斜晶系,空间群都为P1,单晶结构分析表明,在配合物1中,中心铜( Ⅱ)原子具有畸变三角双锥构型[Cu N3Cl2];配合物2是配位聚合物,每个重复单元有3个Cd( Ⅱ)原子和2个不同的Cd( Ⅱ)配位中心,Cd1( Ⅱ)原子具有中心对称的畸变八面体构型Cd Cl4N2,Cd2( Ⅱ)原子具有畸变的八面体构型Cd Cl4N2。     

微乳液介质中1,5-二(2-羟基-5-溴苯)-3-氰基甲月替光度法测定微量铅

铅是对人体有害的元素,如果人们经常食用被铅污染的食品,铅就会在人体内积累,引起慢性中毒。目前,铅的测定方法主要有原子吸收光谱法、分光光度法、原子荧光光谱法、气相色谱法和电化学法等,其中分光光度法具有简便、快速     

基于2-(4-苯基-1,2,3-三唑)亚甲基吡啶(PTMP)的过渡金属配合物的合成与晶体结构

本文报道了一类基于 2-(4-苯基-1,2,3-三唑)亚甲基吡啶(PTMP)配体的过渡金属镍、钴和锌配合物的合成,并通过单晶衍射实验确定了它们的晶体结构。研究结果表明,在这类金属配合物中,PTMP 均通过吡啶氮原子和 1,2,3-三唑中的 2 位氮原子与金属配位,并形成了六元螯合环。在 Co髤及 Ni髤的配合物中,有 2 个 PTMP 参与配位,配位数为 6,配合物的空间构型是畸变的八面体;而在 Zn髤中则只有 1 个 PTMP 参与配位,配位数为 4,配合物的空间构型是变形的四面体。晶体结构数据分析及理论计算结果表明,尽管 PTMP 分子中 1,2,3-三唑环上的 2 位氮原子相对于 3 位氮原子而言,电子云密度较低,但在这类配合物中由于"螯合效应"2 位氮原子仍然表现出了较强的配位能力。     

3-苯氧基甲基-4-(4-甲基苯基)-5-(2-吡啶基)-1,2,4-三唑的铜( Ⅱ)、镉( Ⅱ)配合物的合成、晶体结构和光学性质（英文）

以3-苯氧基甲基-4-(4-甲基苯基)-5-(2-吡啶基)-1,2,4-三唑(L)为配体分别合成了2个金属配合物即[Cu2L2Cl4]·2H2O(1)和[Cd3L2(μ2-Cl)6]n·2n CH3CN(2),对其进行了红外、紫外、热重、粉末衍射、元素分析和晶体结构等表征。配合物1和2都属于三斜晶系,空间群都为P1,单晶结构分析表明,在配合物1中,中心铜( Ⅱ)原子具有畸变三角双锥构型[Cu N3Cl2];配合物2是配位聚合物,每个重复单元有3个Cd( Ⅱ)原子和2个不同的Cd( Ⅱ)配位中心,Cd1( Ⅱ)原子具有中心对称的畸变八面体构型Cd Cl4N2,Cd2( Ⅱ)原子具有畸变的八面体构型Cd Cl4N2。     

一步法2-氨基-1-苯乙酮盐酸盐、醛和巯基乙酸三组分反应高效合成噻唑烷酮

采用一步法在二异丙基乙胺存在下由2-氨基-1-苯乙酮盐酸盐、芳香醛和巯基乙酸三组分反应高效合成了噻唑烷酮。该反应显示出很好的化学选择性。首先2-氨基-1-苯乙酮的N原子与芳香醛选择性反应生成席夫碱,然后巯基乙酸的S原子亲核进攻席夫碱的C原子,最后N原子与羧酸基团环加成生成噻唑烷酮。合成的化合物用光谱技术进行了表征。     

氯化银沉淀分离-氢化物发生-原子荧光光谱法测定银锭中硒和碲

硒和碲是银锭中的主要有害杂质元素,依据国家银锭标准[1],硒和碲是必检项目。目前,其测定方法有国家标准方法电感耦合等离子体原子发射光谱法(ICP-AES)[2],而这种仪器成本和运行费用十分昂贵,且检出限较高。近年来,氢化物发生-原子荧     

导数-原子捕集-火焰原子吸收光谱法测定中草药中的微量铜

研究了在原有基础上对原子捕集装置的改进，并与导数原子吸收光谱法结合，使铜的测定灵敏度有较大提高。在10mV/min灵敏度档下，捕集时间为2min时，方法的检出限和特征浓度分别为0.52和0.85μg/L，分别较常规火焰原子吸收法改善1和2个数量级。利用该法成功测定了甘草、柴胡等10味中药中的微量铜，平均回收率为94.2%－104％。     

酶-金属单原子复合催化剂在一锅法生物-化学反应的应用（英文）

酶催化与金属单原子催化结合,理论上可开发众多新的绿色化学合成反应,是催化科学的一个重要研究前沿方向.酶-金属单原子复合催化剂兼具酶和金属单原子催化剂的高效、高立体选择性等优点.目前已成功构建的单原子分散金属催化剂的载体一般为刚性的无机载体,利用柔性蛋白分子作为载体制备单原子分散金属催化剂的技术瓶颈问题在于蛋白分子具有柔性、构象易变的特点,并且氨基酸残基与金属原子之间的相互作用力较弱,蛋白分子表面的氨基酸残基难以与金属单原子稳定结合.针对这样一个关键技术瓶颈问题,我们建立了酶-金属单原子复合催化剂的光化学合成方法.本文研究酶-金属单原子复合催化剂在生物-化学一锅级联反应合成联苯类手性醇中的催化性能.联苯类手性醇是手性药物的重要中间体,通常通过多步化学法或生物-化学级联法制备.相比于多步化学法,利用生物-化学级联反应制备联苯类手性化合物具有反应条件温和、选择性高、环境友好等优点.采用光化学法合成脂肪酶-钯单原子复合催化剂(Pd₁/CALB-Pluronic),通过球差矫正扫描透射电镜和扩展X射线吸收精细结构表征复合催化剂的形貌.首先研究了Pd₁/...     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

Hard and soft acids and bases: structure and process

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).