非配位性溶剂中CdS纳米颗粒的生长动力学及其机理研究

本文以氧化镉为镉源，硫单质为硫源，油酸为配体，在十八烯体系中合成单分散的CdS纳米颗粒。通过改变油酸的浓度，研究了油酸对颗粒的生长动力学、颗粒尺寸分布以及颗粒浓度的影响。所得到的CdS纳米颗粒直径从2．2—4．5nm变化，最大荧光发射波长为450nm。在油酸浓度为297M，反应时间为60min左右时，所得到的CdS颗粒直径为4．5nm，而颗粒浓度仅为10^-5M；在油酸浓度为42mM时，实际可得到的CdS颗粒的直径可小至2．2nm，反应溶液中颗粒的平均浓度可达到8×10^-5M左右。研究表明，油酸浓度增大，使初始成核速度加快，反应平衡时所得到的纳米颗粒直径较大，但是颗粒数目显著减少，并且尺寸分布也有所增宽。

NO的配位性

NO是奇电子分子.它的11个电子排布在(1σ)~2(2σ)~2(3σ)~2(4σ)~2(1π)~4(5σ)~2(2π)~1.其中(1σ)~2的成键作用与(2σ)~2的反键作用大致抵消,(3σ)~2的成键作用与(5σ)~2的反键作用大致抵消.NO分子是由(4σ)~2的强σ键和(1π)~4(2π)~1的π键结合起来的.(2π)~1是反键电子,总键级为2.5.(5σ)~2的能级(14.61ev)与N的2P能级(14.5ev)接近,(5σ)~2电子对可看成是NO中N原子上的孤电子对,在形成配合物时,可做给出电子对,表现出Lewis碱性.(2π)~1轨道还能接受电子,表现出LeWis酸性.NO属于π酸配体.这样NO就能生成大量的配合物.

双β-二酮配体配位性的理论研究

基于自洽反应场(SCRF)中的极化连续介质模型(PCM),采用密度泛函理论B3LYP/6-31G**计算了以二硫醚和芳环为桥基的两类双β-二酮配体的空间构型和电子结构,结合其配合物晶体结构数据,研究配体分子电子结构与配位性的关联性.结果表明,配体分子的几何构型、前线轨道、偶极矩和电荷布居,与配合物构型、活性配位原子和配位形式(单核或多核、分子内或分子间)之间的关联性与一致性十分有意义.配体的理论计算研究可以在一定层次上为配合物几何结构特征和配位特性提供合理的分析与预测.

六次甲基四胺合钴(Ⅱ)配合物的室温固相合成及其热色性

以六水合二氯化钴与六次甲基四胺为原料通过室温固相反应制得了钴(Ⅱ)-六次甲基四胺配合物,采用化学分析I、R、DTA和TG等手段对合成产物进行了表征,并与液相合成法进行了比较,结果表明:配合物中Co(Ⅱ)与六次甲基四胺的物质的量之比为1∶2,将六水合二氯化钴与六次甲基四胺以不同比例混合反应,所得的产物组成都为CoCl2.2C6H12N4.6H2O,该配合物具有良好的热致变色性能.

壳聚糖基金属配合物材料及其应用现状

壳聚糖是从虾、蟹等甲壳纲动物中提取的一种天然碱性高分子多糖 ,对过渡金属及稀土金属具有良好的配位作用 ,以壳聚糖及改性壳聚糖为基质 ,络合金属离子所得壳聚糖基金属配合物材料具有许多优异的性能 ,做为一种配合物材料在酶固定化剂、分离膜、人工尿素吸附剂、纳米微晶的生长诱导剂、化学催化剂、植物生长调节剂以及金属分离及含量检测等领域有着良好的应用前景 ,本文对壳聚糖基金属配合物的结构、性质及在上述领域的应用进行了简要综述 .

Design and synthesis of two coordination polymers for the rapid detection of ciprofloxacin based on triphenylpolycarboxylic acid ligands

Two coordination polymers were synthesized by hydrothermal reaction,namely,[Cd(H_(3)cpbda)(2,2′‑bipy)(H_(2)O)]_(n)(1)and[Mn(H_(3)cpbda)(phen)(H_(2)O)]_(n)(2),where H_(5)cpbda=5,5′‑[(5‑carboxy‑1,3‑phenyl)bis(oxy)]triisophthalic acid,2,2′‑bipy=2,2′‑bipyridine,phen=1,10‑phenanthroline.The two complexes were characterized by single‑crystal X‑ray diffraction,powder diffraction,infrared spectroscopy,and thermogravimetric analysis.Complexes 1 and 2 are“V”‑shaped 1D chains,and the molecules form 2D(1)and 3D framework(2)structures through weakπ…πstacking.Furthermore,complex 1 was dispersed in an aqueous solution and its fluorescence intensity demonstrated excellent stability.Complex 1 can specifically detect ciprofloxacin in urine with a detection limit of 1.91×10^(-8)mol·L^(-1).CCDC:2359498,1;2359499,2.

Syntheses and catalytic performances of three coordination polymers with tetracarboxylate ligands

Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed hydrothermally using H4adip(H4adip=5,5′-azanediyldiisophthalic acid),phen(phen=1,10-phenanthroline),bipy(bipy=2,2′-bipyridine),bpa(bpa=bis(4-pyridyl)amine),and zinc and cobalt chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffrac-tion analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the orthorhom-bic system Pnna(1 and 2)or P21212(3)space groups.All compounds exhibit 3D frameworks.The catalytic perfor-mances in the Henry reaction of these compounds were investigated.Compound 3 exhibited an effective catalytic activity in the Henry reaction at 70℃.CCDC:2339391,1;2339392,2;2339393,3.

Syntheses,crystal structures,and catalytic properties of three zinc(Ⅱ),cobalt(Ⅱ)and nickel(Ⅱ)coordination polymers constructed from 5⁃(4⁃carboxyphenoxy)nicotinic acid

Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3.

Chiral fluorescent sensor Tb^(3+)@Cd‑CP based on camphoric acid for the enantioselective recognition of R‑and S‑propylene glycol

Herein,a layered chiral coordination polymer,[Cd2(D‑cam)_(2)(2,2′‑bipy)_(2)]_(n)(Cd‑CP),was synthesized using a solvothermal method with camphoric acid(D‑H_(2)cam),2,2′‑bipyridine(2,2′‑bipy)and Cd^(2+),and Tb^(3+)@Cd‑CP was in‑situ synthesized introducing Tb^(3+)ions.The fluorescence experiments revealed that compared to Cd‑CP,Tb^(3+)@Cd‑CP exhibited ultra‑high fluorescence performance.The luminescence sensing performance demonstrated that Tb^(3+)@Cd‑CP could distinguish R/S‑propylene glycol(R/S‑PG)by fluorescence responses,with fluorescence quenching constant of 5.3×10^(3)and 2.0×10^(3)L·mol^(-1)respectively and the enantioselectivity factor(α)of 2.65.Moreover,Tb^(3+)@Cd‑CP demonstrated limits of detection of 9.3 and 19.0μmol·L^(-1)for R‑PG and S‑PG,respectively,and showed good reproducibility.

Transition metal coordination polymers with flexible dicarboxylate ligand:Synthesis,characterization,and photoluminescence property

Under solvothermal conditions,six new coordination polymers(CPs)[Mn(L)(phen)(H_(2)O)]_(n)(1),[Co(L)(phen)(H_(2)O)]_(n)(2),[Cu(L)(phen)(H_(2)O)]_(n)(3),[Zn_(2)(L)_(2)(phen)2(H_(2)O)]_(n)(4),[Zn(L)(phen)]_(n)(5),and[Cd(L)(phen)2]_(n)(6)were synthesized by reactions of dicarboxylate ligand 2,2'-(1,2-phenylenebis(methylene))bis(sulfanediyl)dinobutyric acid(H_(2)L)and 1,10-phenanthroline(phen)with the corresponding metal salts.Complexes 1-6 have been structurally characterized by single-crystal X-ray diffraction analyses,elemental analysis,IR,thermogravimetric analysis,and powder X-ray diffraction.The structures of 1-6 are 1D chains,which are further connected by hydrogen bonding interac-tions to form 3D supramolecular structures.Among them,1 and 2 are isomorphic with L2-of syn-conformation,while L2-shows anti-conformation in 3-6.In addition,the solid-state photoluminescence property of 4-6 was investigated.

Synthesis,crystal structure and adsorption properties of a novel Fe(Ⅲ) porous coordination polymer containing 1,4-naphthalenedicarboxylate ligand

A novel porous coordination polymer,iron naphthalenedicarboxylate Fe（OH）（1,4-NDC）·2H2O is hydrothermally synthesized by the reaction of FeSO4·7H2O and 1,4-naphthalenedicarboxylic acid（1,4-H2NDC） at 150℃.The compound crystallizes in a tetragonal space group P42/nmc：a=2.1447（4） nm,c=0.68849（14） nm,V=3.1669（11） nm3,Z=8,R=0.0845,wR=0.1829.The crystal structure exhibits a three-dimensional framework which is composed of infinite chains of corner-sharing octahedral Fe（OH）2O4 with 1,4-NDC ligands forming two types of channels with square-shaped cross-sections.The large channels present a cross-section of 0.76 nm×0.76 nm,while the small channels are about 0.30 nm×0.30 nm.No structural transformation occurs after removing the guest water molecules,while a robust structure generates with permanent porosity.The adsorption measurements show that the anhydrous sample of the compound can adsorb CO2 into its pores.The adsorption isotherms for methanol,acetone,tetrahydrofuran and benzene are also measured.

Microsatellite Alterations on Chromosome 8 of Hepatocellular Carcinoma

Objective: To study the features of microsatellite alterations on chromosome 8 and their asso- ciation with clinicopathological characteristics of hepatocellular carcinoma (HCC). Methods: Ten highly- polymorphic microsatellite markers on chromosome 8 were selected to be detected for loss of heterozygosity (LOH), microsatellite instability (MSI) and allelic imbalance (AI) in 56 HCC using MegaBACE 500 auto- matic DNA analysis system. Results: LOH was found in 37 of 56 HCC (66.1%) on at least 1 locus, and the top three loci were D8S261(53.5%), D8S1721(52.5%) and D8S1771(52.5%). LOH frequency on D8S277 was signi?cantly higher in cases positive for serum HBsAg than in those negative for HBsAg (P <0.01). Similarly, LOH on D8S261, D8S298 and D8S1733 occurred more frequently in patients with negative HB- sAg than those with positive HBsAg (P <0.01). LOH on D8S298 and D8S1771 was more frequent in those tumors larger than 3 cm in size (P <0.05 or P <0.01). LOH frequencies of D8S1721 were signi?cantly higher in the patients with absent or not intact tumor capsule than in those with intact tumor capsule (P <0.05). LOH on D8S298 and D8S1771 was more frequently detected in tumors with intrahepatic metastasis than in those without intrahepatic metastasis (P <0.01). MSI was found in 12.5% (7/56) cases, and AI was found in 19.6% (11/56), no correlation was found between MSI and AI and clinicopathological character- istics of HCC. Conclusion: Frequent microsatellite alterations on chromosome 8 existed in HCC. LOH, which represents tumor suppressor gene pathway, plays a more important role in hepatocarcinogenesis; MSI representing mismatch repair gene pathway ranks next. LOH at a particula locus is associated with the clinicopathological parameters of human HCC.

Recent developments in the use of single-atom catalysts for water splitting

Electrochemical water splitting is regarded as the most promising approach to produce hydrogen.However,the sluggish electrochemical reactions occurring at the anode and cathode,namely,the oxygen evolution reaction(OER)and the hydrogen evolution reaction(HER),respectively,consume a tremendous amount of energy,seriously hampering its wide application.Recently,single-atom catalysts(SACs)have been proposed to effectively enhance the kinetics of these two reactions.In this minireview,we focus on the recent progress in SACs for OER and HER applications.Three classes of SACs have been reviewed,i.e.,alloy-based SACs,carbon-based SACs and SACs supported on other compounds.Different factors affecting the activities of SACs are also highlighted,including the inherent element property,the coordination environment,the geometric structure and the loading amount of metal atoms.Finally,we summarize the current problems and directions for future development in SACs.

Identification of Phase and Sex-related ISSR Markers of Red Alga Gracilaria lemaneiformis

Six ISSR primers are employed to display the polymorphism of different phases and sexes of red alga Gracilaria lemaneiformis, and two of them, P1 and P3, amplified distinct band patterns. The ISSR pattern amplified by primer P1 of the female gametophyte is identical to that of tetrasporophyte, but distinct from that of male gametophyte. Of the bands produced by primer P3, one is specific to female gametophyte. Three morphologically similar fronds can be easily identified using ISSR technique. Two specific markers, SM1 andSF3, related to male gametophyte and female gametophyte, are cloned and sequenced. The homologous sequences of SM1 are found to encode a hypothetical protein. There is no homologous sequence of SF3 that can be found in GenBank.

Syntheses, Structures and Magnetic Properties of Two Co(II) Coordination Polymers with 2,5-Pyridine Dicarboxylic Acid

The hydro(solvo)thermal reactions of cobalt powder or its chloride with 2,5- pyridine dicarboxylic acid (H2PYDC) yielded two new complexes: [Co(II)2(PYDC)2(H2O)2- (H2O)4]n 1 and {Co(II)[NH2(CH3)2]2(PYDC)2}n 2. It is observed that the reactive solvents result in different connectivity modes of ligand and diverse dimensional extension of crystal structures. The correlation between structure and magnetic property will be discussed in this paper. Crystal data for 1: space group P1, a = 7.0419(17), b = 8.937(2), c = 9.6182(19) ?, α = 91.532(4), β = 99.869(10), γ = 107.889(11)o, V = 565.5(2) ?3, Z = 1, Dc = 1.845 g/cm3, μ = 1.56 mm-1, F(000) = 322 , R = 0.0505 and wR = 0.1580; and those for 2: space group C2/c, a = 14.9075(6), b = 8.2523(3), c = 16.9643(2) ?, β = 100.982(2)o, V = 2048.75(11) ?3, Z = 4, Dc = 1.560 g/cm3, μ = 0.892 mm-1, F(000) = 996, R = 0.0443 and wR = 0.1134.

A new 3-D element formulation on displacement of steel-concrete composite box beam

Slip of a composite box beam may reduce its stiffness, enlarge its deformation and affect its performance. In this work, the governing differential equations and boundary conditions of composite box beams were established. Analytic solutions of combined differential equations were also established. Partial degree of freedom was adopted to establish a new FEA element of three-dimensional beam, taking into account the slip effect. Slip and its first-order derivative were introduced into the nodes of composite box beams as generalized degree of freedom. Stiffness matrix and load array of beam elements were established. A three-dimensional nonlinear calculation program was worked out. The results show that the element is reliable and easy to divide and is suitable for special nonlinear analysis of large-span composite box beams.

Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquids： Effect of Specific Ions and Reaction Parameters

Caffeic acid phenethyl ester(CAPE)is a rare,naturally occurring phenolic food additive.This work systematically reported fundamental data on conversion of caffeic acid(CA),yield of CAPE,and reactive selectivity during the lipase-catalyzed esterification process of CA and phenylethanol(PE)in ionic liquids(ILs).Sixteen ILs were selected as the reaction media,and the relative lipase-catalyzed synthesis properties of CAPE were measured in an effort to enhance the yield of CAPE with high selectivity.The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE.[Emim][Tf2N]was selected as the optimal reaction media.The optimal parameters were as follows by response surface methodology(RSM):reaction temperature,84.0°C;mass ratio of Novozym 435 to CA,14︰1;and molar ratio of PE to CA,16︰1.The highest reactive selectivity of CAPE catalyzed by Novozym 435 in[Emim][Tf2N]reached 64.55%(CA conversion 98.76%and CAPE yield 63.75%,respectively).Thus,lipase-catalyzed esterification in ILs is a promising method suitable for CAPE production.

Redox behavior and chemical species of arsenic in acidic aqueous system

Arsenic(As)removal from smelting acidic wastewater is an urgent task.The most common method is oxidation of trivalent As(III)to pentavalent As(V)subsequently precipitated by ferric(Fe(III))salts.Foundations of redox behavior and chemical species are of great importance for understanding As removal.In this work,cyclic voltammetry(CV)and UV?Vis spectroscopy were used for laboratory observation;meanwhile HSC and MINTEQ software were employed for theoretical analyses.It is found that As(III)oxidation,a multiple electron transfer reaction,is diffusion-controlled.The oxidation over-potential is very high(about0.9V)in sulfuric acid solutions(pH1.0).In addition,Fe(III)?As(V)complexes are evidenced by UV?Vis spectra and chemical species analyses in series of Fe(III)?As(V)?H2SO4?H2O solutions.Therefore,the Fe(III)and As(V)species distribution against pH values are determined and a newφ?pH diagram with inclusion of Fe?As complexes is consequently compiled based on thermodynamic data predicted by other researchers.

Crystal Structure of (3S, 6S, 7R, 8R)-3,6-Bis-diphenylphosphino-1,4-dioxabicyclo〔3.3.0〕octane

The title compound, C30H18O2P2, is a chiral biphospbine ligand. Itscrystal structure was determined by X-ray diffraction analysis. The crystal is or-thorhombic I space group, P212121 1 greement factor for 2326 independent reflections with (I)- In the molecu1e, two diphenylphosphino groups are in the same side of two rigidtetrahydrofuran rings and point out from each other resulting in the non-chelate charac-ter of this bidentate ligand, the title compound.

Ammonium cobalt phosphate with asymmetric coordination sites for enhanced electrocatalytic water oxidation

Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.