疏水性咪唑类混合离子液体的物理化学性质

本文选取疏水性和疏水性离子液体混合物作为研究对象, 将疏水性离子液体1-甲基-3-n-丁基咪唑三氟甲基磺酰胺盐[BMImN(CF3SO2)2]与BMImPF6以不同的比例进行混合, 对混合离子液体及其相应单组分离子液体进行了相关物理化学性质的测试和对比, 讨论由于混合导致的物理化学效应.     

表面活性剂胶束化物理化学性质研究

通过电导法考查温度和盐浓度对十二烷基硫酸钠(SDS)临界胶束浓度(CMC)的影响,研究表面活性剂形成胶束过程的物理化学性质。根据拟相分离模型求得胶束化热力学函数,并讨论体系电导活化能随温度和SDS浓度变化关系。结果表明:SDS的CMC随温度升高而增加,随氯化钠浓度增大而减小。在热力学上SDS在水溶液中形成胶束是一个自发、放热、熵增的过程;在动力学上,SDS溶液电导率与温度关系符合Arrhenius公式,通过电导活化能信息可揭示离子型表面活性剂形成胶束的机理特征。     

Frontispiece: Controlled Self-assembly of Gold(I) Complexes by Multiple Kinetic Aggregation States with Nonlinear Optical and Waveguide Properties

Introduction of multiple kinetic aggregation states (Aggs) into the self-assembly pathway could bring complexity and flexibility to the self-assemblies, which is difficult to realize due to the delicate equilibria established among different Aggs bonded by weak noncovalent interactions. Here, we describe a series of chiral and achiral d¹⁰ Au^I bis(N-heterocyclic carbene, NHC) complexes, and the achiral complex could undergo self-assembly with multiple kinetic Aggs. Generation of multiple kinetic Aggs was realized by applying chiral or achiral seeds exhibiting large differences in elongation temperatures for their respective cooperative self-assembly processes. We further showed that the chiral Au^I self-assemblies having non-centrosymmetric packing forms exhibit nonlinear optical response of second harmonic generation (SHG), while the SHG signal is absent in the achiral analogue. The crystalline achiral Au^I self-assemblies could function as optical waveguides with strong emission polarization.     

Tuning Chemical and Physical Properties of Phosphorus Corroles for Advanced Applications

Although the affinity of metallocorroles to axial ligands is quite low, this is not the case when the chelated element is phosphorus. This work is hence focused on the mechanism of ligand exchange of six-coordinate phosphorus corroles as a tool for affecting their chemical and physical properties. These fundamental investigations allowed for the development of facile methodologies for the synthesis of a large series of complexes and the establishment of several new structure/activity profiles that may be used to understand and predict spectroscopic features and for tailor-made modification of photophysical and electrochemical properties. This is exemplified by the facile access to complexes with terminal groups that are of large potential for practical applications based on click chemistry, optical imaging, and surface science.     

Physical and Chemical Properties of Dissolved Electrons (Excess Electrons)

Electrons produced in a gaseous, liquid, or solid solvent are called dissolved electrons or excess electrons. These excess electrons can exist as quasi-free particles of high mobility in a delocalized state, comparable with electrons in a metal; or as bound particles of low mobility they can be localized within narrow limits—in a solvent cavity formed by repulsive forces. Localized electrons can also be solvated like normal ions. Characteristically, such solvated electrons exhibit broad and extensive absorption spectra in the visible to near infrared spectral range. The localized and delocalized states of the excess electrons can be in equilibrium with each other, such that a continuous transition of the properties between the limiting extremes can be observed. The reactions of the excess electrons with suitable acceptors (substrates) are initiated by an attachment-detachment equilibrium A + e^? ? A^? which is followed by further chemical rearrangements. The rate constants of these reactions vary by more than 15 powers of ten depending on the substrates and the solvents. Most of the properties of excess electrons in solution can be interpreted by means of a model which is easily understandable but quantitatively evaluated only with considerable effort.     

The Effect of Filtration on Physical and Chemical Properties of Osmo-Dehydrated Material

Osmotic dehydration (OD) performed in concentrated fruit juices used as osmotic solution (OS) comes with some limitations resulting from the material cell structure and is not entirely recognized at the moment. Filtration of the juice could provide some insight into the phenomena occurring throughout the OD. Therefore, the main aim of the study was to recognize the mechanism of selective penetration during OD and evaluate the effect of filtration on physical and chemical properties of osmo-dehydrated material. For this purpose, OD of pumpkin in non-filtrated and filtrated (filters 0.2, 0.45, 0.8, 1.2, 3, 5 and 8 μm) concentrated chokeberry juice was carried out in the study. Moreover, scanning electron microscope (SEM) images were provided. Total phenolic content (TPC) and antioxidant capacity measured by Ferric Reducing Antioxidant Potential (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC ABTS) of OS and the material were determined. It was found that even though filtration of osmotic solution had a moderate influence on the mass transfer, it greatly affected the chemical composition of dehydrated material. The best option, considering both chemical and physical properties of the dehydrated material, is the use of non-filtrated solution. However, when shorter time of OD is considered, much better results are obtained for filtrated solutions.     

Thermodynamic Properties and Molecular Dipole Moments of Antimony Compounds from Quantum Chemical Evaluations

By the PM3 method, standard values of entropy, heats and Gibbs energies of formation and dipole moments of the molecules have been computed for a series of inorganic and organic antimony compounds. Linear dependences P exper = bP theor (where P is any of the mentioned properties) have been stated, allowing a priori evaluation of thermodynamic characteristics and molecular dipole moments of Sb-containing substances. It has been concluded that triphenylstibinedichloride in benzene solution, as well as triphenylstibinehydroxychloride in dioxane medium, exist in the form of trigonal bipyramid with two axial chlorine and oxygen atoms.     

电拓扑状态指数在有机污染物理化性质和毒理学性质预测中的应用

电拓扑状态指数既表征了各原子在分子中的拓扑信息,也描述了分子中所有原子之间的电性关系.本文概述了电拓扑状态指数的原理和特点,描述了电拓扑状态指数在预测有机污染物理化性质及毒理学性质中的应用.对建立的定量构效关系/定量结构性质关系(QSAR/QSPR)模型的分析表明,有机污染物的沸点、色谱保留指数、溶解度等理化性质以及生物毒性、生物降解性与电拓扑状态指数均具有良好的相关性.     

A Quantum Chemical Study of Bismuth Compounds Thermodynamic Properties and Configuration of Pentacoordinated Organobismuth Molecules

By the PM3 method, standard values of entropy, heats, and free energies of formation have been computed for a series of inorganic and organic bismuth compounds. Linear dependences P exper = b P theor (where P is any of the mentioned properties) have been stated, allowing a priori evaluation of thermodynamic characteristics of Bi-containing substances. A quantum chemical calculation reproduces well the adiabatic ionization potential of BiH 3 . Triphenyldichlorobismuth and triphenyldinitratobismuth existence in benzene solutions in the form of trigonal bipyramid with two axial chloro and nitrato ligands has been concluded.     

不同MgO担体对Ba-Ru/MgO氨合成催化剂物化性质和反应性能的影响

采用不同沉淀剂制备了MgO材料,以其为载体制备了Ba-Ru/MgO氨合成催化剂,考察了沉淀剂种类和BaO助剂对其氨合成性能的影响.通过X射线衍射(XRD)、N2物理吸附、X射线荧光光谱(XRF)、透射电镜(TEM)、H2程序升温还原(H2-TPR)、CO2程序升温脱附(CO2-TPD)、H2程序升温脱附(H2-TPD)和N2程序升温脱附(N2-TPD)表征手段,对不同沉淀剂影响Ba-Ru/MgO催化剂氨合成性能的原因进行了探索.结果表明:采用(NH4)2CO3作沉淀剂制备的Ba-Ru/MgO催化剂表面Ru物种易于在低温下还原,催化剂表面在低温区具有较多数量的弱碱性吸附位,在450℃、5.0 MPa和5 000 h-1条件下,由(NH4)2CO3做沉淀剂制备的Ba-Ru/MgO催化剂活性最高,出口氨浓度为3.74%.BaO助剂的加入大大减少了Ba-Ru/MgO催化剂表面吸附氢的数量,增大表面脱附氮的数量,从而易于N2解离吸附,提高氨合成反应速率.     

Syntheses,Structures, and Properties of Lanthanide Supramolecular Complexes with 1, 10‐Phenanthroline and Terminal Amino Acids with Different Chain Lengths

Four lanthanide supramolecular coordination compounds, [Eu(gly)₂(phen)₂(H₂O)₂](ClO₄)₃(phen)₄ · H₂O ( 1 ), [Eu₂(APA)₆(phen)₂](ClO₄)₆(phen)₄ · 3H₂O ( 2 ), [Tb₂(ABA)₄(phen)₄](ClO₄)₆(phen)₄ ( 3 ), and [Eu₂(AHA)₄(phen)₄](ClO₄)₆(phen)₂ · 2H₂O · 2C₂H₅OH ( 4 ) (gly = glycine, APA = 3‐aminopropionic acid, ABA = 4‐aminobutanoic acid, AHA = 6‐aminohexanoic acid, phen = 1, 10‐phenanthroline), were synthesized and characterized by single crystal X‐ray diffraction. Compound 1 has a 2‐D supramolecular layered structure of mononuclear coordination cations and free phen molecules connected via hydrogen bonding and π‐π stacking interactions. 2 forms a 3‐D supramolecular network by hydrogen bonding between binuclear coordination cations and free phen molecules, between coordination cations and lattice water molecules, and π‐π stacking interactions between free phen molecules. Compounds 3 and 4 form 2‐D supramolecular structures with π‐π stacking between coordinating phen molecules, and between free phen molecules hydrogen‐bonded to the binuclear coordination cations. The high‐resolution emission spectra show only one Eu³⁺ ion site in the title complexes. The aqueous solutions of the title complexes are all photochromic with the color of the solution changing from yellow to green when irradiated by mercury lamp. During the decoloration process, they return to yellow color.     

季铵盐型表面活性剂的合成及物化性能测定

从脂肪酸和N-(2-羟乙基)乙二胺开始,经过咪唑啉中间体,合成了12种未见文献报道的新化合物,其中3种为具有不同类型特性基团的新型两性表面活性剂、3种为新型阳离子表面活性剂,并测定了它们的物化性能。     

Polyethylene Aerogels with Combined Physical and Chemical Crosslinking: Improved Mechanical Resilience and Shape‐Memory Properties

While the introduction of polymers into aerogels strongly enhances their toughness, truly elastic monolithic aerogels which restore their dimensions upon extensive compression are still challenging to synthesize. In this context hydrophobic semi‐crystalline polymers with low glass transition temperatures, and combined stiffness and flexibility, have only recently attracted attention. Shown here is that polyethylene aerogels with a low density, and combined chemical crosslinking and high crystallinity, display high moduli and excellent mechanical resilience. To maximize the crystallinity of these aerogels while maintaining a high crosslinking density, polyethylene networks with well‐defined segments were synthesized by hydrosilylation crosslinking of telechelic, vinyl‐functionalized oligomers obtained from catalyzed chain‐growth polymerization. Recoverable deformations both above and below the melting temperature of polyethylene affords remarkable shape‐memory properties.     

草坪剪草绿色素的提取与性质

本文研究了从草坪剪草中提取绿色素的方法，理化性质和稳定性，提取方法简便，在碱性和中性环境下，色素对热，光和大部分金属离子都是稳定的。     

Syntheses,Crystal Structure,and Magnetic Properties of a Self‐assembling Dicopper(II) Helicate with Novel Bipyridine Ligand

A novel double helical dicopper(II) complex was synthesized by reaction of a polydentate ligand L = 2,2′‐bipyridyl‐6,6′‐bis(2‐acetylpyrazinohydrazone) with copper(II) perchlorate in CH₃CN. The self‐assembling process was studied by UV‐Vis spectrometric titration experiments which revealed the formation of dinuclear complexes [Cu₂L₂](ClO₄)₄. The structure of dicopper double‐helicate was confirmed by X‐ray diffractometry. Each copper(II) center occupies a distorted octahedral environment. Variable‐temperature magnetic measurements reveal weak antiferromagnetic interactions between Cu(II) ion centers with J = ?0.63 cm^?1.     

Physical and Chemical Properties of Large Metal and Semiconductor Clusters in View of Future Applications

Metal and semiconductor clusters in the nanometer size regime exhibit quantum size behavior which is demonstrated by means of scanning tunneling spectroscopy and scanning capacitance microscopy on single clusters. Cluster monolayers can be prepared by self-assembly processes on modified surfaces of substrates. Clusters in the channels of nanoporous alumina are promising candidates not only for a novel kind of cluster arrangement for future electronic applications but also for the easy generation of light emitting diodes.     

Acid-Cleavable Aromatic Polymers for the Fabrication of Closed-Loop Recyclable Plastics with High Mechanical Strength and Excellent Chemical Resistance

Although closed-loop recycling of dynamic covalent bond-based plastics does not require catalysts, their mechanical strength and chemical stability remain a major concern. In this study, closed-loop recyclable poly(aryl imine) (PAI) plastics with high mechanical strength and excellent chemical resistance are fabricated by copolymerizing aromatic amines and aromatic aldehydes through dynamic imine bonds. The resulting PAI plastic with a tensile strength of 58.2 MPa exhibits excellent chemical resistance and mechanical stability in acidic and basic aqueous solutions and various organic solvents. The PAI plastics can be depolymerized in a mixed solvent of tetrahydrofuran (THF)/HCl aqueous solution through the dissociation of imine bonds, and the monomers can be facilely recovered with high purity and isolated yields due to the solubility difference between the aromatic amines and aromatic aldehydes in selective solvents. The efficient closed-loop recycling of the PAI plastic can also be realized through monomer conversion because the hydrolysis of the aromatic aldehydes generates aromatic amines. The recovered monomers can be used to re-fabricate original PAI plastics. This PAI plastic can be selectively recovered from complicated mixed polymer waste streams due to the mild depolymerization conditions of the PAI plastic and its high stability in most organic solvents.     

Silver(I) Complexes with Dithioether Ligands: Syntheses,Crystal Structures,and Fluorescence Properties

Two new dithioether ligands, 1,4‐bis[(phenylsulfanyl)methyl]naphthalene ( L¹ ), and 4,4′‐bis[(tert‐butylsulfanyl)methyl]biphenyl ( L² ) were synthesized and their silver(I) complexes were studied. Both Ag^I complexes, [Ag L¹ (NO₃)]_n ( 1 ) and [Ag L² (NO₃)]₂ ( 2 ), were synthesized at ambient temperature and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction analysis. Single‐crystal X‐ray analysis shows that complex 1 has a one‐dimensional helical chain structure with the neutral repeating unit [Ag(μ₂‐ L¹ )(NO₃)], whereas complex 2 has a centrosymmetrical neutral dinuclear structure. Moreover, complexes 1 and 2 are further extended into three‐dimensional supramolecular frameworks by hydrogen bonding and π–π stacking interactions, respectively. In addition, complexes 1 and 2 display strong blue emission in the solid state at room temperature.