聚/N-异丙基丙烯酰胺-铕-噻吩甲酰三氟丙酮的光谱性质及能量传递的研究

首次合成了铕-聚(N-异丙基丙烯酰胺)-噻吩甲酰三氟丙酮(Eu3+-PNIPAM-TTA)三元配合物,并用紫外光谱、红外光谱和荧光光谱进行了初步表征.结果表明,Eu3+与PNIPAM侧链中氮原子或氧原子配位,Eu3+-PNIPAM-TTA体系为三元配合物,而并非PNIPAM与铕-噻吩甲酰三氟丙酮(Eu3+-TTA)的混合物;Eu3+-PNIPAM-TTA三元配合物的614 nm波长荧光强度比Eu3+-PNIPAM及Eu3+-TTA二元配合物分别增强了20900%和183%,在能量传递中,高分子以F(o)rster能量传递方式将紫外激发能传递给TTA,再经TTA传递给Eu3+,而获得增强的Eu3+的特征发射.并考察了不同合成条件下的荧光光谱性质.     

稀土配合物/改性MCM-41杂化发光材料的合成研究

采用水热法合成了改性MCM-41中孔分子筛;采用液相沉淀法合成了Eu(Phen)2(Pht)2Cl.H2O和Eu(Phen)2(Sal)(Pht)Cl.H2O两种稀土有机配合物。并将所制备的稀土有机配合物组装到改性MCM-41中,合成了稀土配合物(铕)/改性MCM-41杂化发光材料,采用小角XRD、红外光谱、荧光光谱和TEM、N2吸附-脱附对其结构和荧光性质进行了研究。结果表明,组装体具有MCM-41典型结构并且在组装之后仍保留了MCM-41的孔道结构;其荧光光谱具有Eu3+的特征荧光发射,发光强度大于纯配合物,更有利于实际应用。     

过渡金属离子调控微孔铕络合物的荧光性能研究

金属铕(Ⅲ)与3,5-二羧基吡啶(pdc)形成配合物:[Eu(pdc)1.5(DMF)]·(DMF)0.5(H2O)0.5—(1a)。1a受热失去自由水和DMF后形成配合物(2a)—[Eu(pdc)1.5]。结构分析表明配合物2a拥有一维规整的大小为6.3×8.5的六边形孔道,并且未配位的吡啶N原子都朝向空腔,能够吸附亲N原子的过渡金属离子,从而改变原配合物的发光性能。通过对不同价态以及不同浓度金属离子对配合物2a的荧光调控性能分析,发现低浓度金属离子对配合物2a的发光强度起到敏化作用,高浓度金属离子则出现猝灭效应。另外,在10-5 mol/L相同浓度不同金属离子对配合物荧光性能影响中,Cu2+离子敏化效果最强,Fe3+离子的则最弱。     

一种喹啉苯腙的合成及其对金属离子的识别

以4-硝基苯肼、8-羟基喹哪啶等为原料设计合成了8-羟基-2-喹啉甲醛-4-硝基苯腙(1),经元素分析、1H NMR对其结构进行了表征。在V(二甲亚砜)/V(甲醇)=1∶9混合溶剂中采用UV-Vis光谱法研究了苯腙(1)对Li+、K+、Mg2+、Ca2+、Mn2+、Co2+、Ni2+、Zn2+、Cd2+、Hg2+、Fe2+、Fe3+及Cu2+离子的识别性能。结果表明,苯腙1仅对Cu2+和Zn2+有特殊的识别能力,加入Cu2+或Zn2+的苯腙1溶液由黄色分别变为橙色和红色,其光谱在413 nm处的吸收峰强度减小,且分别在485和508 nm附近产生新的吸收峰。竞争实验表明,苯腙1对Zn2+的检测不受除Cu2+以外上述其它阳离子影响,而对Cu2+的检测不受上述任何其它阳离子的影响。线性拟合结果显示,苯腙1与Cu2+和Zn2+分别形成了1∶1和1∶2的配合物。     

SiO_2凝胶玻璃中Eu~(3+)、Tb~(3+)与1,10-邻菲罗啉配合物的原位化学合成及其荧光和热学性能

应用原位化学复合方法，将Eu3＋、Tb3十与1；10-邻菲罗啉配合物光学均匀复合到SiO2凝胶玻璃中，解决了因稀土含氮配合物易水解而难以用溶胶-凝胶工艺将其均匀掺入无机基质的问题研究了原位配合物的荧光和热学性能结果表明，由于配合物的形成使稀土离子特征荧光强度显著增加，而无机基质的保护作用则使原位配合物的热稳性提高200℃以上化学合成纯配合物Eu（Phen）2Cl3·2H2O的高分辨荧光谱表明，Eu3+在其中的格位对称性为C1或C2或C3．     

Eu-SSA-phen/MCM-41杂化发光材料的合成与表征

采用水热法合成改性MCM-41介孔分子筛;采用液相沉淀法合成了以磺基水杨酸及邻菲罗啉作为双配体的铕的配合物,找到其发光效果最好的配比,即n(Eu)∶n(SSA)∶n(phen)=1∶2∶1,并将发光效果最好的稀土配合物组装到改性后的MCM-41中,合成了稀土配合物(Eu)/改性MCM-41杂化发光材料,采用紫外光谱分析、元素分析、小角XRD、红外光谱、荧光光谱和TGA对其结构和荧光性质进行了研究。结果表明,组装体具有MCM-41典型结构并且在组装之后仍保留了MCM-41的孔道结构;其荧光光谱具有Eu3+的特征荧光发射,发光强度大于纯配合物。改性MCM-41后组装稀土配合物的发光效果更佳,热稳定性更好,更有利于实际应用。     

辐射法制备布洛芬金属分子印迹聚合膜

以消炎镇痛药(S)-布洛芬与Cu2+配合物为模板分子,以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,聚砜膜为多孔支撑层,利用辐射引发聚合制备了Cu2+配位分子印迹复合膜。通过紫外光谱研究发现,(S)-布洛芬、Cu2+和甲基丙烯酸形成了配位比为1∶2∶2的3元配合物。通过扫描电镜及渗透实验发现聚砜基膜固含量为17%时,修饰后印迹膜形态及性能最好。同时,通过选择渗透实验发现,印迹膜对其手性对称物(R)-布洛芬及结构类似物酮洛芬渗透选择性较差。     

硅烷改性铕配合物的制备与发光性能研究

荧光稀土配合物具有良好的荧光特性,但是简单的配合物由于较低的光、热稳定性而限制了其应用。以氨丙基硅烷偶联剂与邻苯二甲酰氯反应制备改性配体,并与铕离子进行配位制备改性稀土配合物,通过天线效应敏化稀土离子发光,从而实现能量传递和最终的材料发光。考察了不同条件下对稀土配合物的产率和荧光发射强度的影响;测量了配合物的红外光谱、紫外光谱,并推测了配合物的稳定结构;通过荧光光谱测定了配合物的荧光发射强度。结果表明,改性配合物表现出了更强的铕离子的荧光特征峰,说明了铕离子的第一激发态能级和改性配体的三重态能级之间有更好的匹配。     

改性灰D(GDSA)与Cu2+离子形成配合物的紫外-可见光谱及偏光性能

将直接染料灰D(GD)重氮化后与磺基水杨酸(SSA)偶合得到一种三偶氮染料(GDSA),研究了GDSA与Cu2 离子配合系统的紫外-可见光谱,发现Cu2 与GDSA在pH=4.6的条件下可形成配合物[Cu(Ⅱ) (GDSA)],其表观稳定常数K表＝6.2×105.将该配合物与聚乙烯醇共混制成偏光膜,研究了膜的光谱吸收特性,结果表明,掺有[Cu(Ⅱ) (GDSA)]的膜的偏光性能明显优于掺有GD的膜,偏光度＞60%的波长区间由GD膜的100nm(550～650nm)增加到320nm(350～670nm),并使200～280nm范围紫外光的透过率＜5%.     

识别Cu2+的中氮茚衍生物荧光探针分子的设计与合成

合成了荧光性能良好的中氮茚化合物5,用IR、1 H NMR等手段表征其结构;研究各种金属离子对其荧光性能的影响,结果表明Cu2+能显著地猝灭其荧光,而余者则几无影响;其紫外吸收峰值随着Cu2+浓度的增加而增加,表明二者存在着化学反应。此化合物有望作为重金属离子Cu2+的荧光探针。     

Synthesis and Characterization of Some Transition Metal Chelates of 5-(1-Hydroxy-6-Naphthylazo-3-Sodium Sulphonate) Thiobarbituric (L1) and Barbituric (L2) Acids

1.IntroductionThereisaconsiderableinterestinthechemistryofbarbituricandthiobarbituricacidderivativesbecauseoftheirabilitytofunctionaschelatingagentsutilizedfortheanalyticaldeterminationofalargenumberoftransitionmetalions[1~6].Theaimofthepresentstudyistoprepareandelucidatethestructureofthemetalchelatesformedbycombinationof5-(1-hydroxy-6-naphthylazo-3-sodiumsulphonate)thiobarbituricandbarbituricacidswithsometransitionmetalions(VO'+,Mn'+,Fe3+lCos+)Niz+andCu:+).2.ExperimentalAllthechemicalsused…     

Infrared-visible sum frequency generation investigation of Cu corrosion inhibition with benzotriazole

Infrared-visible sum frequency generation spectroscopy is used to investigate the corrosion inhibitor benzotriazole (BTAH) adsorbed on Cu(100) and Cu(111) in acidic solution. Potential-dependent in situ spectra indicate that the adsorbed molecule is the benzotriazole anion (BTA-) at all potentials investigated. The Cu(100) surface is shown to form an ordered adlayer at all potentials probed, while the Cu(111) face is shown to be disordered at negative potentials, but to order with applied positive potential. The ordered adlayer is shown to consist of the BTA- in two configurations, one coordinated to the surface and Cu+ ions in solution and the other coordinated only to the surface. The BTA- coordinated to Cu+ is shown to be more stable with respect to Cl- addition than BTA- coordinated to only the surface. This study demonstrates the viability of using sum frequency generation to study corrosion inhibition in situ.     

Multicolor luminescence from transition metal ion (Mn2+ and Cu2+) doped ZnS nanoparticles

Mn and Cu doped ZnS nanoparticles in powder form were prepared by a simple solvothermal route. Particle size and crystal structure of the products were investigated through X-ray diffraction study revealing the formation of cubic ZnS nanoparticles of average diameter 2.5 nm. Particle size was also verified by the high resolution transmission electron microscopic images. Blue emission at approximately 445 nm was observed from the undoped sample, which was attributed to the presence of large surface defects. With increasing doping concentration the defect related emission gradually quenches and subsequently the impurity related emissions appeared. Mn doped samples exhibited orange emission at approximately 580 nm which may be attributed to the transition between (4)T1 and (6)A1 energy levels of the Mn2+ 3d states. Whereas, the Cu doped ZnS nanoparticles exhibited a red shifted strong blue emission at approximately 466 nm which is attributed to the transition of the electrons from the surface states to the 't2' levels of Cu impurities.     

Application of a poly(4-styrenesulfonate) liquid binding layer for measurement of Cu2+ and Cd2+ with the diffusive gradients in thin-films technique

A diffusive gradients in thin films (DGT) technique for measuring Cd and Cu is described using, for the first time, a liquid phase binding layer and a dialysis membrane diffusive layer. The binding phase was a 0.020 M solution of poly(4-styrenesulfonate) (PSS) polyelectrolyte using a specially designed DGT deployment device. The binding properties of Cd2+, Cu2+, and a range of alkali and alkaline earth metal ions to the PSS solution were characterized. The PSS behaved like a cation exchanger with preferential binding to Cd2+ (6.0 micromol mL(-1), log K = 9.0) and Cu2+ (2.5 micromol mL(-1), log K = 8.1) under competitive binding conditions. PSS had a substantial binding capacity at pH > 3 and at competitive Na+ concentrations up to 1.0 M. The DGT devices were successfully validated for Cd2+ (accumulated mass vs time r2 = 0.969, recovery compared with predicted values = 98%) and Cu2+ (r2 = 0.980, recovery = 98%) in synthetic lake water (Windermere). Validation was also undertaken for Cu in a spiked local lake water (Parkwood Pond) (r2 = 0.981, recovery = 46%). The low recovery here was due to complexation of Cu by natural organic matter (14 mg C L(-1)). Field deployments of the DGT devices were successful at measuring Cu concentrations of 0.031-0.63 microg L(-1) in local fresh and salt waterways. These DGT-labile measurements were 0.05-39% of the 0.45-microm-filtered Cu values.     

[Cu(1,4-C4H12N2)2(ClO4)2]n(H2O)2n,a novel butane-1,4-diamine-bridged two-dimensional copper(II) square network: Synthesis,structure, and magnetic properties

A novel butane-1,4-diamine-bridged copper(II) compound was synthesized via solvent diffusion route with high yield. Each copper is coordinated by four butane-1,4-diamine ligands, each of which in turn links with two copper atoms to form a two-dimensional (2D) square network. Interestingly, the title compound features a cross-linking rhombic channel (ca. 5.06 × 14.73 Å) parallel to the crystallographic b axis. And magnetic result measured indicates the presence of localized unpaired electrons in the structure and thus the cupric Cu(II) state.     

Catalytic effect of nanogold on Cu(II)-N2H4 reaction and its application to resonance scattering immunoassay

In the medium of EDTA-NaOH, nanogold strongly catalyzed the slow reaction between hydrazine (N2H4) and Cu(II) to form Cu particles, which exhibited a strong resonance scattering (RS) peak at 602 nm. The increased RS intensity at 602 nm (DeltaI(RS)) was linear to the nanogold concentration in the range of 0.008-2.64 nM, with a detection limit of 1.0 pM Au. The rate equation obtained by the initial rate procedure was V(Cu) = K(Cu)[C(Cu(II))](2)C(OH)(1)C(Au)(1)C(N2)H4(1), with an apparent activation energy of 38 kJ x mol(-1), and the catalytic reaction mechanism was also discussed. An immunonanogold-catalytic resonance scattering spectral (RSS) assay was established for detection of microalbumin (Malb), using 10 nm nanogold to label goat antihuman Malb to obtain an immunonanogold probe (AuMalb) for Malb. In pH 5.0 citric acid-Na2HPO4 buffer solution, the AuMalb aggregated nonspecifically. Upon addition of Malb, it reacted with the probe to form dispersive AuMalb-Malb immunocomplex in the solution. After centrifugation, the supernatant containing AuMalb-Malb was obtained, and exhibited a catalytic effect on the reaction of N2H4-Cu(II) to produce large Cu particles that resulted in the I(602 nm) increasing. The increased RS intensity at 602 nm (DeltaI(602 nm)) was linear to Malb concentration (C(Malb)) in the range of 0.4 to 460 pg x mL(-1), with the regression equation of DeltaI(602 nm) = 0.3713 C(Malb) + 7.2, correlation coefficient of 0.9981 and detection limit of 0.1 pg x mL(-1) Malb. The proposed method was applied to detect Malb in healthy human urine samples, with satisfactory results.     

阴离子（NO3－／Cl －／SO2－4）对 Ni（OH）2晶型及其结构稳定性的影响

采用超声波辅助沉淀法分别在单元掺杂、二元掺杂和不掺杂三种情况下制备了三种不同镍源的纳米氢氧化镍,研究三种阴离子（NO3－,Cl－,SO2－4）对产物晶相结构及稳定性的影响。结果表明：未掺杂时,半径较大的SO2－4离子有利于α‐Ni（OH）2的形成;在单掺杂Co（Ni2＋∶Co2＋＝1∶0．20）时,NO3－离子不仅有利于α‐Ni（OH）2的形成,而且可以使α‐Ni（OH）2在碱液中保持较高的稳定性;当复合掺杂Co／Cu（Ni2＋∶Co2＋∶Cu2＋＝1∶0．15∶0．05）时,三种镍源制得的样品均为纯α‐Ni（OH）2结构,但以Ni（NO3）2为镍源的α‐Ni（OH）2在碱液中结构稳定性较高,NiCl2次之,NiSO4较差。可见,α‐Ni（OH）2结构及稳定性既与掺杂情况有关,也与阴离子密切相关。     

镀铜废水中Cu2+含量的5,6-二氯-苯并噻唑偶氮苯甲酸显色光度法测定

利用5,6-二氯-苯并噻唑偶氮苯甲酸(5,6-diCl-BTAEB)与铜的显色反应,在pH值为5.0的NH4OAcHOAc缓冲溶液中,在乳化剂OP存在下,使5,6-diCl-BTAEB与Cu2+反应生成2:1稳定的配合物,可实现对Cu2+的测定.其最大吸收波长为650 nm,表观摩尔吸光系数为5.57×104L/(mo...     

Quantum-spin-liquid states in the two-dimensional kagome antiferromagnets ZnxCu4-x(OD)6Cl2

A three-dimensional system of interacting spins typically develops static long-range order when it is cooled. If the spins are quantum (S=1/2), however, novel quantum paramagnetic states may appear. The most highly sought state among them is the resonating-valence-bond state, in which every pair of neighbouring quantum spins forms an entangled spin singlet (valence bonds) and these singlets are quantum mechanically resonating among themselves. Here we provide an experimental indication for such quantum paramagnetic states existing in frustrated antiferromagnets, Zn(x)Cu(4-x)(OD)(6)Cl(2), where the S=1/2 magnetic Cu2+ moments form layers of a two-dimensional kagome lattice. We find that in Cu(4)(OD)(6)Cl(2), where distorted kagome planes are weakly coupled, a dispersionless excitation mode appears in the magnetic excitation spectrum below approximately 20 K, whose characteristics resemble those of quantum spin singlets in a solid state, known as a valence-bond solid, that breaks translational symmetry. Doping with non-magnetic Zn2+ ions reduces the distortion of the kagome lattice, and weakens the interplane coupling but also dilutes the magnetic occupancy of the kagome lattice. The valence-bond-solid state is suppressed, and for ZnCu(3)(OD)(6)Cl(2), where the kagome planes are undistorted and 90% occupied by the Cu2+ ions, the low-energy spin fluctuations become featureless.     

Mass spectrometric determination of the coordination geometry of potential copper(II) surrogates for the mammalian prion protein octarepeat region

The N-terminal domain of mammalian prion proteins contains several tandem repeats of the octapeptide PHGGGWGQ, each one capable of selectively binding up to 1 equiv of Cu2+. Under saturating conditions Cu2+ is known to coordinate the HGG portion of the repeat sequence via the histidine imidazole side chain, two deprotonated amide N-atoms, and a backbone carbonyl O-atom. Using appropriate selection criteria, we have generated a short list of candidate metal ions (Co3+, Ni2+, Pd2+, Pt2+) that can serve as potential surrogates for Cu2+. The selected metal ions were screened for binding interactions with the OR-derived peptide fragment AcHGGGWNH2 (Ac = acetyl, amino acid residues in italics) using electrospray ionization mass spectrometry. The coordination geometries of these metal ions with the synthetic OR peptide were subsequently determined from fragment analysis using collision-induced dissociation tandem mass spectrometry. Our results indicate that, although Co3+, Pd2+, and Pt2+ all bind to the OR fragment via the peptide backbone to varying extents, each of these metal ions appears to associate with the peptide in a unique manner, which is distinct from the way in which Cu2+ is coordinated. This work illustrates the extremely strong selectivity for Cu2+ of this highly conserved region of the mammalian prion protein.