有机化合物中二级化学键的理论研究(Ⅳ)——喹啉基氮杂大环铜配合物中的二级化学键

前文［１,２］报道了二级化学键存在于若干金属有机化合物以及某些簇合物中,实际上,在Ｆｉｇ．１ＣｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｏｆＣｕＬ２［１４］┐２ｑｕ某些配合物体系中亦存在着二级化学键．本文将着重研究喹啉基氮杂环铜配合物（ＣｕＬ２［１４］－２ｑｕ）...     

离子液体1-乙基-3-甲基咪唑三氟甲基磺酸盐与水之间的氢键作用(英文)

通过衰减全反射红外(ATR-IR)光谱、二维红外相关谱结合量子化学计算研究了1-乙基-3-甲基咪唑三氟甲基磺酸盐([emim][OTf])和水之间的氢键作用.结果表明,在[emim][OTf]-水体系中,当水的浓度较低时(0.1x(D2O)0.3),水分子的主要存在形式是包裹在离子液体中的没有缔合的单体.水分子优先填充到[emim][OTf]的空隙中,并且与[emim][OTf]的阴离子形成"[OTf]-…HOH…[OTf]-"结构,水分子与[emim][OTf]的阳离子的相互作用位点是烷基氢而不是芳香氢;当水分子浓度较高时,水分子倾向于自身缔合形成小团簇结构,水分子与[emim][OTf]的阳离子的相互作用位点是芳香氢而不是烷基氢.     

分子光化学贮存太阳能 Ⅲ.双环[2,2,1]-2,5-庚二烯的光诱导电子转移敏化异构化反应

以N,N,N′,N′-四甲基联苯二胺、2,6-二甲氧基萘和2,7-二甲氧基萘为光敏剂,在正己烷溶液中实现了双环[2,2,1]-2,5-庚二烯到四环[2,2,1,0^2,6,0^3,5]庚烷的异构化。测定了反应的量子产率。讨论了反应机理。通过激发态的光敏剂与二烯之间的电子转移反应,形成单重态和三重态处于平衡状态的离子自由基对中间体。处于溶剂笼中的三重态离子自由基对经电子反传,产生激发三重态二烯。最后该激发态二烯经分子内[2+2]环合加成反应异构化为四环烷。     

1-丁基-3-甲基咪唑硫酸氢盐离子液体与含氮化合物相互作用的理论研究

采用密度泛函理论方法研究了1-丁基-3-甲基咪唑硫酸氢盐离子液体[Bmim]HSO_4与氮化物喹啉和吲哚分子的相互作用,并进行了NBO和AIM分析。[Bmim]HSO_4离子对最稳定结构表明,[HSO_4]~-阴离子中的氧原子与咪唑环中正电性较大的C14-H20之间有较强的氢键作用。在分子水平上,NBO和AIM分析证实了喹啉和吲哚分子与[Bmim]HSO_4的阴离子之间有较强的相互作用,其中,喹啉分子中的氮原子与阴离子[HSO_4]~-中氢原子之间的作用以及吲哚分子中N-H的氢原子与[HSO_4]~-中氧原子之间的作用是该离子液体能够有效脱除氮化物的主要动力。     

Matrix Isopotential Synchronous Fluorescence Spectroscopy for Direct Determination of 1-Hydroxypyrene as a Urinary Biomarker of Exposure to Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are present ubiquitously in the environment and exposure to PAHs is a major environmental and occupational health problem. One important approach in assessing human exposure to PAHs is to measure 1-hydroxypyrene excreted in urine. Its present analytical methods require either chromatographic separation^[1] or solvent extracting^[2]. Matrix isopotential synchronous fluorescence spectroscopy (MISFS) is a new fluorimetric technique which consists of performing synchronous scans through a trajectory joining points of equal intensity on a total fluorescence spectrum^[3]. The technique is very useful for resolving highly-spectrally-overlapped mixtures or detecting analytes in complex fluorescent background without the need for tedious prior separation.     

[C3mim][NTf2]/DEC/[Li][NTf2]体系的基础性质

The hydrophobic ionic liquid (IL) 1-propyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C₃mim][NTf₂]) was synthesized according to traditional methods. By adding different amounts of diethyl carbonate (DEC) solvent and lithium bis[(trifluoromethyl)sulfonyl]imide ([Li][NTf₂]) salt to [C₃mim][NTf₂] IL, eight solution systems were prepared. First, the thermodynamic properties of the eight solution systems were characterized by differential scanning calorimetry (DSC). The semi-stable temperature of the system gradually disappeared with increasing lithium salt content, but the melting point temperature was not apparent in the experiment. These results indicate that DEC and lithium salts can dissolve in ILs within the tested temperature range. The basic properties of the eight systems, including thermodynamic and dynamic properties, were systematically studied at different temperatures. The variation in the self-diffusion coefficient of lithium ion ([Li]⁺) as a function of DEC concentration, density changes, viscosity, conductivity, and the viscosity/conductivity activation energy of the eight systems was calculated by the Vogel Fulcher Taman (VFT), Final Vogel Fulcher Taman (FVFT), and Arrhenius equations. The effect of temperature on the properties of the system was studied in detail. Within the temperature range measured herein, the deviation between the fitting equation and experimental value was small. Consequently, these equations were successfully used to calculate the properties of the system at various temperatures. All fitting parameters of the corresponding equations are provided herein. The viscosity for all systems decreased rapidly with increasing temperature, which increased the conductivity. Based on these experiments, the influence of DEC on the system microstructure was discussed in the context of the molecular dynamics simulation results. In particular, the interaction between [Li]⁺ and [NTf₂]^-/DEC was examined. In all solution systems, [NTf₂]^- coordinates to [Li]⁺ through only the O atom and not the N atom. Radial distribution function (RDF) analysis showed that the interaction between [Li]⁺ and [NTf₂]^- weakened with increasing DEC concentration. DEC molecules were observed in the first solvation layer of [Li]⁺ coordinating to [Li]⁺ through the carbonyl O atom. Although the interaction between [Li]⁺ and DEC was weakened, competition between [NTf₂]^- and DEC in the first solvation layer of [Li]⁺ was observed by the coordination number analysis of the O atom around [Li]⁺. Therefore, the introduction of DEC is beneficial for Li⁺ diffusion, which is consistent with the experimental results.     

Solvent Sublation for Surface-Active Substances from Aqueous Solution,Comparison with Solvent-Extraction

The solvent sublation technique, a non-foaming technique, is originated by Sebba^[1] as an option for ion flotation, in which the surface active solute in water is adsorbed on the surface of ascending bubbles and then collected in an immiciable solvent As we know that there are a number of features that make the technique more advantageous than that of the solvent extraction:the possibility of easy handling of large volumes of aqueous sample; the equilibrium state established not in the bulk of system but only at the aqueous-organic interface and the recovery of trace elements eventually reaching 100%; no emulsion formation^[2-3]. Furthermore, the effluent water from a sublation column doesn't require further treatment to remove residual solvent. The handles are single and expenses are cheap, so the solvent sublation has the potential in the environmental treatment and the separation and preconcentration process^[4-6]. The aim of this paper is to investigate the experimental possibilities of the solvent sublation and its intercomparison with conventional liquid-liquid extraction, in order to get more information on widely applications in the near future.     

Quantitative analysis of fluorimated ethylchloroformate derivatives of non-protein amino acids using positive and negative chemical ionization gas chromatography-mass spectometry

The GC-MS characterization of the ethylchloroformate derivatives of amino acids in an aqueous medium has been applied to non-protein amino acids. Derivatization of non-protein amino acids using ethylchloroformate, trifluoroethanol, and pyridine produced strong [M + 1]⁺ and [M - 1]⁻ ions in positive and negative chemical ionization (CI) modes, respectively. Twenty-one out of the twenty-three non-protein amino acids studied produced detectable ion chromatograms in both ionization modes when methane was used as the CI reagent gas. Mass spectra of these non-protein amino acid derivatives showed characteristic [M - 19]⁺, [M + 1]⁺, [M + 29]⁺, and [M + 41]⁺ peaks in the positive chemical ionization mode, and [M - 1]⁻, and [M + 35]⁻ peaks in the negative chemical ionization mode. The detection limits and the linear dynamic range of trifluorethanol ethylchloroformate derivatives of non-protein amino acids were studied using positive chemical ionization. The detection limits are mostly in the femtomole range.     

激光解吸电离飞行时间质谱下的银簇行为

近年来,对金属簇的研究已成为化学与物理学中最活跃的研究领域之一［１］．金属簇被认为是介于单个原子与固体之间的中间相［２］．深入地研究其结构、形成机理及物理与化学行为,对于寻找新的催化剂［３］,重新认识气相化学与凝聚相化学的关系［４］,都有非常重要的意...     

AFM Tip-Directed ID and 0D Assembling of Colloidal Au Nanoparticles on Silicon

Colloidal Nanoparticles have received renewed interests recently from the viewpoint of nanoscale science and technology. Using chemical assembling techniques, one can fabricate well-organized 2D nanoparticle arrays on solid substrates and use it as the Coulomb island for room temperature single electron tunneling^[1], as nanoelectrode for electrochemistry studies^[2], as active substrate for surface enhanced Raman scattering (SERS)^[3,4],as lithographic mask for fabrication of nanostructures^[5] and etc.     

A STUDY OF THE STABILIZING CAPACITY OF GLYCINE TOWARD SILVER CLUSTER Ag42+ IN AQUEOUS SOLUTION

本文用溴钨灯照射含异丙醇、甘氨酸(稳定剂)和硝酸银的水溶液制得非金属银团簇Ag₄²⁺(λmax=275nm),其产率随甘氨酸量的增加而增加,并且在空气中甘氨酸可以稳定其数天。对所得结果以及Ag₄²⁺在照相潜影形成过程中的可能作用进行了讨论。本文用溴钨灯照射含异丙醇、甘氨酸(稳定剂)和硝酸银的水溶液制得非金属银团簇Ag₄²⁺(λ_max=275nm),其产率随甘氨酸量的增加而增加,并且在空气中甘氨酸可以稳定其数天。对所得结果以及Ag₄²⁺在照相潜影形成过程中的可能作用进行了讨论。     

光致电子转移对Rhodamine 6G基态分子结构影响的非共振Raman光谱研究(英文)

基于非共振Raman光谱和量子化学计算,研究了在纯电子给体N,N-二乙基苯胺(DEA)溶剂中Rhodamine 6G(Rh6G+)基态分子结构的变化,这有利于理解该体系中的光致分子间电子转移(PIET).与PIET相耦合的所有振动模式已被确定和指认.结果表明:对应于氧杂蒽环且位于675 cm-1处最主要的振动模式对PIET有着至关重要的贡献;通过与电荷转移复合物(Rh6G/DEA+)的发色团芳香族环的C―C伸展振动模式作比较,C=C伸展振动对PIET的影响更敏感.本文的研究工作能为具有合适电子转移特性的光伏器件中分子结构或溶剂环境的设计提供新颖的观点.     

Study on the Dye-Doped Funcionalized Silica Nanoparticles for The Recognition of SmIgG+B Lymphocytes

The development of sensitive non-isotopic detection sys tem for biological and medicinal applications, such as single cell analyse, DNA sequence, clinical diagnose etc., has driven nanomaterials more towards cell biology and ultrasensitive immunoassay^[1]. Semiconductor nanoparticles have been used for coupling biomolecules but suffer from some disadvantages including poor solubility in water, blinking properties or low quantum yields^[1,3,4]. In this paper, we developed a novel dye-doped functionalized silica nanoparticles and used for detection of SmIgG⁺ B lymphocytes.     

Quantum Chemistry Studies on the Heteropoly Blues of Molybdosilic Series with α-Keggin Structure

ＱｕａｎｔｕｍＣｈｅｍｉｓｔｒｙＳｔｕｄｉｅｓｏｎｔｈｅＨｅｔｅｒｏｐｏｌｙＢｌｕｅｓｏｆＭｏｌｙｂｄｏｓｉｌｉｃＳｅｒｉｅｓｗｉｔｈα－ＫｅｇｇｉｎＳｔｒｕｃｔｕｒｅＦＵＱｉａｎｇ,ＹＡＮＧＭｉｎｇ,ＣＨＥＮＢｉｎ,ＷＡＮＣＥｎ－Ｂｏ,ＸＩＥＤｅ－...     

E-R分子轨道定域化方法与分子结合能

自编了E-R^[1]定域化计算程序,对HF、LiH、BH、Li₂、Be₂、CO和CH₄等分子作了计算。确定的酉变换算出的定域分子轨道正确。计算了各分子的定域分子轨道能量ε、加和能E′和结合能E″^[2],得到三点结论。     

Synthesis of Heterocyclic Compounds from 2-Phenyl-l,2,3-Triazole-4-Formylhydrize

Many compounds containing the 1,3,4-oxadiazole and/or1,2,3(or 4)-triazole and thiadiazole ring system are reported to possess antibacterial^[1], antiinflammatory^[2], anticonrulsant^[3],CNS stimulant^[4] and pesticidal^[5] activities and excellent anthelmintic properties^[6,7]. In view of this and the results of the combined different nuclei system in a molecular always enhancing the therapeutic activities,the present work deals with the synthesis of the combined different pharmacologically active nuclei system mentioned above in a molecular through some new method.     

Conformation Changes of Enkephalin in Coordination with Pb2+ Investigated by Gas Phase Hydrogen/Deuterium Exchange Mass Spectrometry Combined with Theoretical Calculations

In this study, the effects of lead ions(Pb²⁺) on the conformations of leucine encephalin(LE) and methionine encephalin(ME) in gas phase were studied using hydrogen/deuterium exchange mass spectrometry(HDX-MS) and quantum chemistry theoretical calculations at the molecular level. The HDX-MS result revealed that the complexes with the monovalent compounds [LE+Pb–H]⁺ and [ME+Pb–H]⁺had a 1:1 stoichiometric ratio, and different HDX reactivates were observed in a follow of [ME+H]⁺>[LE+H]⁺>[LE+Pb–H]⁺> [ME+Pb–H]⁺. Combining the collision-induced dissociation energies of the complexes and their HDX results, it was found that the more stable the complex, the harder it was for HDX. In addition, the favo-rable conformations of the complexes were obtained by theoretical calculations, revealing that the similar coordination type with diffe-rent bond lengths was obtained. Then, the proton affinity(PA) values of the optimized complexes were calculated to interpret the HDX observations, indicating that the higher the PA values, the more difficult it was for HDX. Overall, the experiments and theoretical calculations revealed that Pb²⁺ could induce conformational changes of LE and ME, and generate ME into a more rigid conformation than LE. The results will prompt further fundamental investigations on the conformational properties of LE/ME in coordination with Pb²⁺.     

D2EHDTPA-TOA反协同萃取镉的速率方程

以恒界面池法研究了D2EHDTPA（二（2-乙基己基）二硫代磷酸）-TOA（三辛胺）反协同萃取镉的界面反应速率方程.萃取历程由若干个相转移（在本体相与界面相之间的物质转移）过程和若干个反应组成.萃取的速率方程为 r=1.42*10^-7[Cd²⁺]^0.42[BHA]^0.47/[B]^0.85[H⁺]^0.21 （mol•m^-2•s^-1） 探讨了萃取速率方程中非整数反应物级数的物理意义.Freundlich因子n越大,物质在界面层所受排斥力越大.萃取过程的表观活化能E=44.2 kJ•mol－1,萃取反应的焓变ΔH=72.9 kJ•mol－1.讨论了由不同的界面模型而导致不能通融的萃取动力学机理的问题.     

Metallosupramolecular Cube with Nanometer-sized Cavitiy

Construction of supramolecular architectures with inner cavities is a subject of current interest because of their abilities for selective inclusion of ions and molecules, molecular recognition and catalysis for specific chemical transformations. The potential use of such species largely depends on their cavity size and type, which are mainly controlled by the ligands via appropriate metal ions. A number of such species with inner cavities have been prepared and characterized. Very recently, several metallosupramolecular capsules with enclosure-like systems and very large inner cavities were reported. Herein reported are a stable neutral nanometer-sized metallosupramolecular cube cage[Ni₆(tpst)₈Cl₁₂] (1) (tpst=2,4,6-tri[(4-pyridyl)sulfanylmethyl]-l,3,5-triazine) with O_h symmetry, which was prepared from assembly reaction of NiCl₂ and the tpst ligand in DMF, and[Ag₇(tpst)₄(ClO₄)₂(NO₃)₅]_n (2) with a single stranded coordination polymer has been synthesized by self-assembly of silver salt and tpst ligand. Polymer 2 contains nanometer-sized tubes with anion and solvent molecule guests.     

Conformational isomers in the photocyclodimerization of N-acylated dibenz[b,f]azepine derivatives

The benzophenone-sensitised photodimerizations of N-acetyl- and N-propionyldibenz[e,f]azepine were investigated in acetone as the solvent. In both the systems, the ¹H NMR analysis of the products revealed two isomeric photodimers differing in the chemical shifts and coupling constants of the cyclobutane protons, aromatic protons and the protons of the acetyl or propionyl group. Upon raising the temperature to ca. 70 °C the signals merge. The findings can be ascribed to a single thermally restricted conformational process such as the rotation about the C–N amide bond. The process exhibits free activation energies: ΔG^#=(74±2) kJ mol⁻¹ (N-acetyl) and ΔG^#=(70±2) kJ mol⁻¹ (N-propionyl).