CRYSTAL STRUCTURE OF SEVEN-COORDINATE TRIPODAL MANGANESE(Ⅱ) COMPLEX

MnC_(24)H_(27)F_(12)N_7O_3P_2·C_2H_5OH, Mr-852, orthogonal, space group P21 3, a=15.220(2);Z=4; V=3525(1)~3; F(000)=1732; Dc=1.61g/cm~3; μ=5.52cm~(-1)(Mo Kα=0.71073). Manganese (Ⅱ) atom is seven-coordinated, with the coordination polyhedron of a monocapped antitrigonal prism.     

《化学进展》2007年度关键词索引

Aγ-Al2O3(9):1322阿尔茨海默病(1):122;(12):2006安培检测法(10):1585氨合成(11):1662氨基酸(6):1016BB细胞淋巴瘤家族(12):1955BDF程序(6):833半胱氨酸(12):1866半合成智能高分子材料(2/3):362包结络合(4):55杯芳烃(5):722二酰亚胺(11):1761苯(5):735苯酚(5):735吡咯(4):520标记(12):1861表面等离子体波共振(SPR)(1):193表面等离子体耦合发射(2/3):256表面活性(9):1291表面两性结构(4):544表面羟基(5):665表面图案化(6):852;(12):1965表面展示技术(1):511,2-丙二醇(5):6511,3-丙二醇(5):651;(7/8):1185丙烯酸(5):643病理(6):893薄…     

四齿配体[Ru(iph)(L)2]2+ (L=cpy,mpy, npy)配合物的结构和光谱特征

采用密度泛函的B3LYP和UB3LYP方法分别优化了一系列[Ru(iph)(L)₂]²⁺ (L=cpy (1), mpy (2), npy (3); 其中iph为2,9-双(1′-甲基-2′-咪唑)-1,10-邻二氮杂菲, cpy为4-氰基嘧啶, mpy为4-甲基嘧啶, npy为4-氮二甲基嘧啶)配合物的基态和激发态结构. 利用含时密度泛函理论(TD-DFT)方法, 结合极化连续介质(PCM)模型计算了它们在丙酮溶液中的吸收和发射光谱. 研究结果表明: 优化得到的几何结构参数和相应的实验值符合得非常好. 1和2的最高占据分子轨道主要由金属的d轨道和iph配体的π轨道构成, 但是3主要占据在npy配体上, 而它们的最低空轨道主要由iph配体的π反键轨道占据. 因此, 1和2的最低能吸收和发射属于金属到配体(MLCT)和配体内部(ILCT)的电荷转移跃迁, 而3属于两个配体之间的电荷转移(LLCT)跃迁. 三个配合物的最低能吸收分别在509 nm (1), 527 nm (2)和563 nm (3), 其磷光发射分别在683 nm (1), 852 nm (2)和757 nm (3). 这显示出通过调节L配体的π电子给予能力可以改变最低能吸收和发射的跃迁性质和发光颜色.     

CRYSYTAL AND MOLECULAR STRUCTURES OF η~8-CYCLOOC-TATETRAENYLLANTHANIDE COMPLEXES [(η~8-C_8H_8)LnCl-(OC_4H_8)_2]_2(Ln=Pr, Nd)

<正> Complexes [(η8-C8H8)LnCl(OC4H8)2]2, (Ln = Pr(1), Nd(2)) both crystallize in monoclinic space group P21/n with cell dimensions for 1: a = 11. 860(3), b=12. 697(3), c=12. 161(2)(?), β=111. 88(2)°, V= 1699. 50(69) (?)3, Dc=1. 66gcm-3,Z==2 (4 monomers), μc=30. 2cm-1, F (000) = 848, the final R = 0. 031, Rw = 0. 032 for 2303 independent reflections with I≥ 3σ(I) ; and for 2: a=11. 834(4), b = 12. 666(5), c=12. 166(3)(?), β=111. 73(2)°, V= 1694. 03 (99)(?)3, Dc= 1. 68g. cm-3, Z = 2 (4 monomers), μc=32. 3cm-1, F(000) = 852, R=Rw = 0. 035 for 3487 independent reflections with I≥3σ(I). In each complex, there are two Ln atoms in a dimeric unit which are bridged asymmetrically by two chloride ions with Ln - Cl bond lengths of 2. 847(2) and 2. 924(2)(?) for 1, or 2. 836(1) and 2. 919(2)(?) for 2. The cyclooctatetraene COT dianion ring is planar with eightfold molecular symmetry and an average C -C bond length of 1. 392(?). It is symmetrically coordinated to the Ln atom with an average Ln - C distance of     

白花蛇舌草中黄酮、多酚、多糖提取工艺及抗氧化研究

本研究利用水浴-回流法提取,分光光度法分析了云南不同产地白花蛇舌草样品中黄酮、多酚、多糖含量;同时,分别研究了不同乙醇体积分数、液料比、提取温度、时间对样品中这3类物质提取效率的影响;此外,利用清除DPPH·自由基的方法,分析了提取液的抗氧化活性,以期为白花蛇舌草资源的利用提供理论和实践指导。结果表明,白花蛇舌草中这3类物质最佳提取条件为乙醇体积分数60%、液料比1:35、温度80℃、时间2. 5 h;不同产地23个样品提取液抗氧化活性IC_(50)(DPPH半数清除率浓度)在0. 18～0. 58 mg·mL~(-1)之间,平均值为0. 35 mg·mL~(-1);相关性分析表明,这些样品中黄酮、多酚含量和IC_(50)值之间呈极显著负相关,相关系数分别为-0. 852和-0. 886(p0. 01),多糖含量与IC_(50)无显著相关性。以上结果表明,水浴-回流法可同时提取白花蛇舌草中黄酮、多酚、多糖三类物质;不同产地样品中这3类物质含量存在差异,这可能与生态因素不同有关;白花蛇舌草中最主要的抗氧化活性物质为黄酮和多酚。     

CRYSTAL AND MOLECULAR STRUCTURE OF A PENTA-COOR-DINATED SILVER COMPLEX, SILVER 8-HYDROXYQUINOLINE-5-SULFONATE AgC_9H_8NO_4S

<正> AgC9H6NO4S, Mr = 332. 1, monoclinic, space group P21/c, a = 8. 292(1), b = 10. 394(2), c=10. 852(2)A, β=102. 73(1)°, V =912. 4(?)3, Z = 4, Dc = 2. 417gcm-3, λ(MoKα) = 0. 71073(?) , μ = 24. 0cm-1, F (000) = 648, final R =0. 041, Rw = 0. 047 for 1369 observed reflections. The coordination polyhedron of Ag(I) is penta-coordinated square pyramid.     

Studies on the Reaction of Vinyl Triazole Derivatives with Hydroxylamine

Vinyltnazoledenvativeshavebeensynthesized1nthesearchforpotentandbroadspectrumfungicides[l.2:.Theyhavebeenfoundtoinhibitbiosynthesisofergosterolinfungalcells[3"'.Inordertodevelopneu:fungicidesweexpectedtosynthesizeaseriesofnewvinyItnazoledenvativesbythereactionof(Z)-or(E)-4,4-dimethyl-1-aryl-2-(1,2,4-triazo1-l-yl)-1-penten-3-ones(I,-.)withhydroxylaminehydrochloride.ButtheresultindicatedthattheproductsII.-,expectedwerenotobtainedandtheneu'heterocycliccompoundsof1,2-oxazocyclopentanedenvatives(…     

Synthesis, Crystal Structure and Antidepressant Activity of 5-[4-(Benzyloxy)phenyl]-9-(n-propyl)-4,6-dioxa-1-azabicyclo[3.3.1]nonane Hydrochloride 0.5Hydrate

The title compound 2(C22H28N+O3)·H2O·2Cl-was synthesized by the reaction of 2-bromo-1-[4-(benzyloxy)phenyl]-1-pentone with 2,2'-azanediyldiethanol. The crystal determined by X-ray diffraction analysis belongs to the monoclinic system, space group Pc with a = 18.312(3), b = 14.838(3), c = 7.6227(14) , β = 97.981(4)°, Z = 2, Mr = 797.82, V = 2051.1(6) 3, Dc = 1.292 g/cm3, S = 0.956, μ = 0.21 mm-1, F(000) = 852, the final R = 0.0625 and wR = 0.1428 for 5683 observed reflections (Ⅰ > 2σ(Ⅰ)). Flack parameter is 0.10(9). The title compound is composed by four non-coplanar ring systems, two benzenes and two morpholines. One morpholine ring (C(3)-C(4)-N(1)-C(1)-C(2)-O(1)) forms a chair conformation, while the other (C(4)-C(3)-O(2)-C(6)-C(5)-N(1)) assumes a boat conformation. X-ray crystal structure displays extensive N-H…Cl and O-H…Cl intermolecular hydrogen bonds. The preliminary antidepressant activity test indicates that the inhibition ratio of SERT (5-HT Transporter) was 35.9% at the dosage of 10.0 mg/L.     

一锅法合成2，4，6-三氯喹唑啉和6-硝基-2，4-二氯喹唑啉

在五氯化磷的存在下,2-氨基-5-氯苯甲酸(1a)或2-氨基-5-硝基苯甲酸(1b)与尿素缩合,一锅法合成了2,4,6-三氯喹唑啉(2a)或6-硝基-2,4-二氯喹唑啉(2b),其结构经1H NMR和ESI-MS表征.合成2a的最佳反应条件为:1a 2.5 mmol,n(1a):n(PCl5):n(尿素)=1.0:6.0:2.2,回流反应1 h,收率41%.     

Studies on synthesis and kinetics of thermodecomposition of the nickel(Ⅱ) compounds with Schiff base derived from amino acids

Monoaqua salicylaldehyde-o-aminobenzoic acid Ni(Ⅱ) monohydrate (cp1) and monoaqua o-vanillin-o-aminobenzoic acid Ni(Ⅱ) monohydrate (cp2) were synthesized. The composition and structures of these two compounds were analyzed. Their thermal stability and non-isothermal kinetics were also investigated by use of TG and DTG curves. The possible reaction mechanisms in their first steps of thermal decomposition reactions were deduced by means of integral and differential methods. Thermodecomposition kinetic equations of the compounds are as follows:Cp1: da/At = A . exp(-E/RT) . 3/2(1 - a)4/3 . [1/(1 - a)1/3 -1]-1 Cp2 : da/At = A . exp(-E/RT) . (1 - a)     

Supervised pattern recognition in food analysis

Data analysis has become a fundamental task in analytical chemistry due to the great quantity of analytical information provided by modern analytical instruments. Supervised pattern recognition aims to establish a classification model based on experimental data in order to assign unknown samples to a previously defined sample class based on its pattern of measured features. The basis of the supervised pattern recognition techniques mostly used in food analysis are reviewed, making special emphasis on the practical requirements of the measured data and discussing common misconceptions and errors that might arise. Applications of supervised pattern recognition in the field of food chemistry appearing in bibliography in the last two years are also reviewed.     

Role of Modern Analytical Chemistry in Material Analyses for Trace Metals

The trend in the modern analytical laboratory is toward lower and lower analytical concentration measurements. The analyst has a variety of analytical instruments and techniques in which to meet the ever growing need for lower concentration measurements with improved precision and accuracy. Techniques available to the analyst include flame and electrothermal atomization-atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma/mass spectrometry, laser enhanced ionization spectrometry, neutron activation analysis, spectrophotometry, isotope dilution mass spectrometry, X-ray fluorescence spectometry, electroanalytical, and chromatography. However, there is no analytical technique that is a panacea for all analytes in the modern analytical laboratory. Steps the analyst must consider to obtain the highest degree of precision and accuracy include the obtaining of a representative sample, the selection of the “best” analytical method, the preparation of the sample, the calibration of the instrumentation, the deciding on the level of effort for the chemical measurement and the evaluation of the data are discussed.     

Chemometrics in pharmaceutical analysis: an introduction, review, and future perspectives

Chemometrics is the application of statistical and mathematical methods to analytical data to permit maximum collection and extraction of useful information. The utility of chemometric techniques as tools enabling multidimensional calibration of selected spectroscopic, electrochemical, and chromatographic methods is demonstrated. Application of this approach mainly for interpretation of UV-Vis and near-IR (NIR) spectra, as well as for data obtained by other instrumental methods, makes identification and quantitative analysis of active substances in complex mixtures possible, especially in the analysis of pharmaceutical preparations present in the market. Such analytical work is carried out by the use of advanced chemical instruments and data processing, which has led to a need for advanced methods to design experiments, calibrate instruments, and analyze the resulting data. The purpose of this review is to describe various chemometric methods in combination with UV-Vis spectrophotometry, NIR spectroscopy, fluorescence spectroscopy, electroanalysis, chromatographic separation, and flow-injection analysis for the analysis of drugs in pharmaceutical preparations. Theoretical and practical aspects are described with pharmaceutical examples of chemometric applications. This review will concentrate on gaining an understanding of how chemometrics can be useful in the modern analytical laboratory. A selection of the most challenging problems faced in pharmaceutical analysis is presented, the potential for chemometrics is considered, and some consequent implications for utilization are discussed. The reader can refer to the citations wherever appropriate.     

Data management in multi-method surface analysis

The solution of the problem of interchangeability of surface analytical data is gaining increasing importance in multi-method surface analysis. There are various surface analytical instruments in different laboratories on several automation levels. For these instruments, which are controlled by computer systems working with proprietary software under various operating systems, a standardised data format is necessary to allow an exchange of data. Therefore, a toolkit has been developed for the transfer, archiving and editing of surface analytical data in a standardised public domain format. This format contains all available and necessary information on experimental conditions and all parameters specific for a number of analytical techniques such as AES, SAM, XPS, SIMS, STM, AFM and EPMA. Additionally, all data concerning the conditions of sample-preparation and measurement history are included in order to allow a well-founded evaluation of the data and improved reproducibility of the experiment.     

Data management in multi-method surface analysis

The solution of the problem of interchangeability of surface analytical data is gaining increasing importance in multi-method surface analysis. There are various surface analytical instruments in different laboratories on several automation levels. For these instruments, which are controlled by computer systems working with proprietary software under various operating systems, a standardised data format is necessary to allow an exchange of data. Therefore, a toolkit has been developed for the transfer, archiving and editing of surface analytical data in a standardised public domain format. This format contains all available and necessary information on experimental conditions and all parameters specific for a number of analytical techniques such as AES, SAM, XPS, SIMS, STM, AFM and EPMA. Additionally, all data concerning the conditions of sample-preparation and measurement history are included in order to allow a well-founded evaluation of the data and improved reproducibility of the experiment.     

A new data management concept for AES and SAM

The problem of interchangeability of surface analytical data is gaining increasing importance in multi-method surface analysis. There are various surface analytical instruments in different laboratories on several automation levels. For these instruments, which are controlled by computer systems working with company-specific software under various operating systems, a standardised data format is necessary to allow an exchange of data. Therefore, we are developing a software package for the transfer, archiving and editing of surface analytical data called MAXMIND (management and exchange of method independent data), which is based on public domain software products. It allows the storage of all available and necessary information on experimental conditions and all parameters specific for a number of analytical techniques such as AES, SAM, XPS, SIMS, STM and AFM. Additionally, all data concerning the sample-preparation and the state of the instrument are included in order to allow a well-founded evaluation of the data and improved reproducibility of the experiment. This concept is demonstrated in detail for the two Auger techniques AES (Auger Electron Spectroscopy) and SAM (Scanning Auger Microscopy).Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday     

基于氧化还原循环信号放大技术的单分子电化学研究进展

现代分析科学的整体发展对分析方法的灵敏度、选择性以及快速响应等有了更高的要求。在单分子水平上实现对目标分子的检测及控制是化学家们长期以来梦寐以求的一项富有挑战性的前沿领域,也是近年来分析科学很重要的前沿发展方向。用电化学方法直接检测单分子面临的一项挑战是单个分子在氧化还原过程中得失电子产生的电流变化太小,现代仪器无法对如此小的电流进行识别。使电极表面氧化还原过程中的电子交换实现多次循环可以放大产生的电流,从而实现单分子水平的直接电化学分析。本文对近期通过循环电子交换过程放大电流信号的技术和装置进行了综述,将各类方法进行对比,并对单分子电化学未来的发展方向进行了展望。     

毛细管电泳分析中的富集技术及其应用

毛细管电泳（CE）具有分析速度快、分离效率高、样品消耗少、成本低廉等优点,已被应用于无机离子、有机小分子、蛋白质、核酸及细胞等的分析中。CE中最常用的检测方式是紫外检测（UV）,但由于常规进样样品体积小、检测光程短,CE-UV的灵敏度往往不能满足复杂样品中痕量物质直接分析的要求。CE中的在柱富集技术包括堆积、动态pH界面、吹扫和瞬间等速电泳等,可在很大程度上提高CE-UV的检测灵敏度;另外,固相和液相微萃取技术及其与在柱富集技术相结合应用在CE中也能净化样品基质,进一步提高富集倍数,改善分析灵敏度,从而拓宽了CE-UV在复杂样品分析中的应用范围。     

LECO600系列气体分析仪新技术的应用

通过对美国LECO公司400和600系列气体分析仪的研究对比，探讨了600系列仪器新技术的运用和改进。而从中也反映了当代分析仪器发展的总趋势。对气体分析仪器的使用者而言也起了推动深入研究其扩大应用和提高对仪器的维护保养水平的作用。