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1.
Poly(N-vinylpyrrolidone)(PVP)nanofibers containing gold nanoparticles were prepared by electrospinning method.This simple route was used to prepare composites on a large scale,and the syntheses are simple.The optical property of gold nanoparticles in PVP aqueous solution was investigated by UV-Visible absorption spectra.The morphology of the fibers and the distribution of particles were characterized by transmission electron microscopy.The structure of the composite was characterized by Fourier transform infrared spectroscopy.  相似文献   

2.
Anisotropic gold nanoparticles (AuNPs) have attracted the interest of scientists for over a century, but research in this field has considerably accelerated since 2000 with the synthesis of numerous 1D, 2D, and 3D shapes as well as hollow AuNP structures. The anisotropy of these nonspherical, hollow, and nanoshell AuNP structures is the source of the plasmon absorption in the visible region as well as in the near‐infrared (NIR) region. This NIR absorption is especially sensitive to the AuNP shape and medium and can be shifted towards the part of the NIR region in which living tissue shows minimum absorption. This has led to crucial applications in medical diagnostics and therapy (“theranostics”), especially with Au nanoshells, nanorods, hollow nanospheres, and nanocubes. In addition, Au nanowires (AuNWs) can be synthesized with longitudinal dimensions of several tens of micrometers and can serve as plasmon waveguides for sophisticated optical devices. The application of anisotropic AuNPs has rapidly spread to optical, biomedical, and catalytic areas. In this Review, a brief historical survey is given, followed by a summary of the synthetic modes, variety of shapes, applications, and toxicity issues of this fast‐growing class of nanomaterials.  相似文献   

3.
Relevant properties of gold nanoparticles, such as stability and biocompatibility, together with their peculiar optical and electronic behavior, make them excellent candidates for medical and biological applications. This review describes the different approaches to the synthesis, surface modification, and characterization of gold nanoparticles (AuNPs) related to increasing their stability and available features useful for employment as drug delivery systems or in hyperthermia and photothermal therapy. The synthetic methods reported span from the well-known Turkevich synthesis, reduction with NaBH4 with or without citrate, seeding growth, ascorbic acid-based, green synthesis, and Brust–Schiffrin methods. Furthermore, the nanosized functionalization of the AuNP surface brought about the formation of self-assembled monolayers through the employment of polymer coatings as capping agents covalently bonded to the nanoparticles. The most common chemical–physical characterization techniques to determine the size, shape and surface coverage of AuNPs are described underlining the structure–activity correlation in the frame of their applications in the biomedical and biotechnology sectors.  相似文献   

4.
聚二茂铁硅烷的合成与性能   总被引:2,自引:0,他引:2  
90年代以来,聚二茂铁硅烷高分子由于其分子量大,溶解性好,可连接功能基侧链等优良性能以及潜在的应用前景而被关注。本文主要对缩聚法,开环聚合法,后功能化等合成方法进行了评述,并对其物理性质以及应用前景进行了探讨。  相似文献   

5.
A variety of gold(Ⅲ) adducts having a-ligated oxygen-donor ligands have been prepared from [Au(ppy)Cl2](ppy.phenylpyridine)(1) either by partial or total replacement of the chloride ions. The new species comprise hydroxo-[Au(ppy)(OH)Cl](2), and [Au(ppy)(OH)2](3), oxo-[Au2(ppy)2(μ-O)2](4), acetate-[Au(ppy)(O2CMe2)] (5), and alkoxo complexes-[Au(ppy)(OR)Cl](6, 7) and [Au(ppy)(OR)2](8--10)(R=Me, 6 and 8; Et, 7 and 9; Pr, 10). The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution(R=Me, Et or Pr) to give the corresponding alkoxides.  相似文献   

6.
Multiple heterohelicenes are a unique class of helical nonplanar scaffolds that have attracted great attention due to their appealing shapes, optical and electronic properties, and potential applications in chiral materials. This review describes the recent advances and challenges in the design and synthesis of representative multiple heterohelicenes with intriguing chiral properties. And the corresponding applications are also covered.  相似文献   

7.

Reaction of potassium tetrachloroaurate(III), KAuCl4, with 2-pyridinecarboxaldehyde (2CHO-py) have been examined in protic HX (X=OH, OMe, OEt, OCH2CH2CH2, OCH2CH2CH2CH3, OCH2CF3) solvents. Compounds in which the pyridine ligand is N or N-O coordinated in a newly carbonyl hydrated or in semi- and acetal-forms, derived by addition of one or two hydroxylic molecules, have been isolated; these include dichloro[pyridine-2(α-hydroxymethanolato)]gold(III) (1), dichloro[pyridine-2(α-ethoxymethanolato)] gold(III) (2), dichloro[pyridine-2[α-(2,2,2-trifluoroethoxymethanolato)]gold(III) (3), trichloro(2-pyridinecarboxaldehyde dimethyl acetal)gold(III) (4), trichloro(2-pyridinecarboxaldehyde diethyl acetal)gold(III) (5), trichloro(2-pyridinecarboxaldehyde di-1-propyl acetal)gold(III) (6) and trichloro(2-pyridinecarboxaldehyde di-1-butyl acetal)gold(III) (7). The crystal and molecular structures of (2), (5) and (7) have been determined by X-ray methods. Compound (2) crystallizes in space group Pna21 with Z=4, a=7.8914(4), b=17.3660(4) and c=8.3873(5)Å; (5) crystallizes in space group P&1macr; with Z=2, a=7.7779(3), b=8.2878(2) and c=13.3202(6)Å, α=96.975(2), β=95.096(2), γ=115.027(2)°; (7) crystallizes in space group P21/a with Z=4, a=14.5438(12), b=8.9865(7) and c=15.0362(11)Å.  相似文献   

8.
Ligand exchange reactions of [NMe4]TeCF3 and CuBr, Ag[BF4] and AuCl have been studied in molar ratios of 2:1. While evidence is found for [Cu(TeCF3)2] moieties by 19F-NMR spectroscopic and mass spectrometric means, [NMe4][Ag(TeCF3)2] and [NMe4][Au(TeCF3)2] were isolated. After cation exchange, the latter compounds were fully characterised as the [PNP] salts ([PNP] = bis(triphenylphosphoranylidene)ammonium). The single crystal structure of [PNP][Au(TeCF3)2] has been elucidated by XRD measurements (P21/a; a = 1765.6(1), b = 1126.0(1), c = 2055.2(1) pm; β = 111.98(1)°; Z = 4).  相似文献   

9.
10.
盒状主体缺电子联吡啶大环的性质、应用和制备   总被引:3,自引:0,他引:3  
何光裕  孙小强  汪信 《有机化学》2004,24(7):745-752,J001
详细描述了盒状主体缺π电子联吡啶大环CPQT的结构和性质,总结比较了它的各种制备方法,并对其与富π电子氢醌醚链衍生物自组装合成索烃、轮烷和准轮烷等方面的应用进行了综述.  相似文献   

11.
The present work provides a brief summary review of the chemistry of luminescent gold(I) alkynyls and their ability to form heterometallic complexes. A series of luminescent heterometallic gold(I)-rhenium(I) alkynyl complexes has been synthesized and characterized. Their electrochemical and photophysical properties have been studied and their emission origins elucidated.  相似文献   

12.
《Analytical letters》2012,45(16):2439-2453
Abstract

A sensitive electrochemical biosensor was designed for determination of aflatoxin B1 (AFB1) using a copper-based metal-organic framework (Cu-MOF), which has strong electrochemical activity and exonuclease III (Exo III)-assisted recycling for dual signal amplification. Hairpin DNA (S1) was immobilized on the electrode. The AFB1 was recognized by aptamer DNA (S2) and complementary DNA (S3) was released. The S3 hybridized with the hairpin S1 to form the Exo III hydrolyzed double-stranded DNA, leaving a partial sequence of hairpin DNA (S1′) on the electrode and releasing S3 for the next cycle of the opening and digestion of hairpin S1. The amplified S1′ then was able to combine with more signal probes. Cu-MOF bond gold nanoparticles (AuNPs) by -NH2 were immobilized to capture DNA (S4) to obtain Cu-MOF/AuNPs/S4. This signal probe Cu-MOF/AuNPs/S4 was able to hybridize with the electrode and generate an amplified electrochemical signal. Under the optimized conditions, this electrochemical biosensor for AFB1 exhibited a low detection limit of 6.7?×?10?7?ng/mL at a signal-to-noise equal to 3 and a wide linear range from 10?6 to 1?ng/mL. The biosensor was also used to analyze AFB1-spiked beer sample with recovery values between 96% and 103%. This method has the potential to become a valuable technology for detecting various toxins by the selection of the appropriate aptamer DNA.  相似文献   

13.
一种新型C60-硫醚衍生物分子在金表面上的自组装   总被引:1,自引:0,他引:1  
报导了一种新型C60 硫醚分子在金表面上自组装膜的形成,并通过接触角、扫描隧道显微术(STM)、X射线光电子能谱(XPS)、电化学和光电化学手段对其进行表征.高分辩STM形貌图证明,在Au(111)基底上C60基团存在并直观显示出特殊的单层膜结构. XPS分析表明,这一新型C60 硫醚分子是通过金硫键固定在金表面上的,并且在组装过程中存在分子内碳硫键断裂步骤.  相似文献   

14.
We report the synthesis of the doubly deprotonated calcium guanidinate, CaC(NH)3, from liquid ammonia and its crystal structure as determined from powder X-ray and neutron diffraction, and confirmed using CNH elemental analysis and infrared (IR) spectroscopy data. CaC(NH)3 crystallizes in the hexagonal system with space group P63/m (no. 176) with Z = 2 and a = 5.2666(13) Å, c = 6.5881(6) Å and V = 158.25(4) Å3. We also compare the structural similarities and differences of this phase with the isotypical strontium and ytterbium compounds.  相似文献   

15.
通过4,4’-一氧二(异氰酸苯酯)与异丙醇加成反应,合成标题化合物 4,4’-一氧二(苯胺灵)(Ⅰ) (C20H24N2O5, Mr=372.41),并用X射线衍射、红外光谱、13C核磁共振、电子轰击质谱和元素分析对标题化合物进行表征. 晶体属于三斜晶系,空间群为P1晶体学参数为: a=0.85107(17), b=0.91164(18), c=1.45701(3) nm, α=80.44(3)°, β=85.25(3)°, γ=62.88(3)°, V=0.9922(3) nm3, Z=2, Dc=1.247 g•cm-3, μ(Mo Kα)=0.90 cm-1, F(000)=396.两个苯环平面之间的夹角为62.06° (0.06°). 晶体结构经全矩阵最小二乘法修正,最终偏离因子R=0.0520, wR=0.1434(对可观察点).此化合物应具有广谱的生物活性.  相似文献   

16.
The yttrium chloride with the bridged bis(amidinate) L (L = Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3) LYCl(DME) (2) was synthesized and structurally characterized. Treatment of LLnCl(sol)x (Ln = Yb, sol = THF, x = 2 1; Ln = Y, sol = DME, x = 1 2) with the dilithium salt Li2L(THF)0.5 afforded the novel bimetallic lanthanide complexes supported by three ligands, Ln22-L)3 · DME (Ln = Yb 3, Y 4; DME = dimethylether), instead of the designed complex LLn(μ2-L)LnL via the ligand redistribution reaction. Complexes 3 and 4 were fully characterized including X-ray analysis and 1H NMR spectrum for 4. Reaction of LnCl3 (Ln = Yb, Y) with 2 equiv. of Li2L(THF)0.5 gave the anionic complexes [Li(DME)3][L2Ln] (Ln = Yb 5, Y 6), which were confirmed by a crystal structure determination. The further study indicated that complexes 3 and 4 can also be synthesized by reaction of LnCl3 (Ln = Yb, Y) with 1.5 equiv. of Li2L(THF)0.5 or reaction of 1 and 2 with anionic complexes 5 and 6. Complexes 3, 4, 5 and 6 were found to be high active catalysts for ring-opening polymerization of ε-caprolactone (CL).  相似文献   

17.
Monometallic and bimetallic diimine complexes of rhenium(I) and osmium(II), [(CO)3(bpy)Re(4,4′-bpy)](PF6) I, [(CO)3(bpy)Re(4,4′-bpy)Re(bpy)(CO)3](PF6)2II, [Cl(bpy)2Os(4,4′-bpy)](PF6) III and [Cl(bpy)2Os(4,4′-bpy)Os(bpy)2Cl](PF6)2IV, and a new heterobimetallic complex of rhenium(I) and osmium(II) [(CO)3(bpy)Re(4,4′-bpy)Os(bpy)Cl](PF6)2V (bpy = 2,2′-bipyridine; 4,4′-bpy = 4,4′-bipyridine) have been synthesized and characterized by various spectral techniques. The photophysical properties of all the complexes have been studied and a comparison is made between the heterobimetallic and corresponding monometallic and homobimetallic complexes. Emission and transient absorption spectral studies reveal that excited state energy transfer from the rhenium(I) chromophore (∗Re) to osmium(II) takes place. The energy transfer rate constant is found to be 8.7 × 107 s−1.  相似文献   

18.
Reaction of [AuIII(C6F5)3(tht)] with RaaiR′ in dichloromethane medium leads to [AuIII(C6F5)3 (RaaiR′)] [RaaiR′=p-R-C6H4-N=N-C3H2-NN-l-R′, (1-3), R = H (a), Me (b), Cl (c) and R′= Me (1), CH2CH3 (2), CH2Ph (3), tht is tetrahydrothiophen]. The nine new complexes are characterised by ES/MS as well as FAB, IR and multinuclear NMR (1H,13C,19F) spectroscopic studies. In addition to dimensional NMR studies as1H,1H COSY and1H13C HMQC permit complete assignment of the complexes in the solution phase.  相似文献   

19.
Silver triflate [AgOTf] assisted de‐bromination gives [Ni(dppm/dppe/(PPh3)2) (OTf)2], which on reaction with 4,4′‐bpy and gold(I) phosphines in dichloromethane medium by the self assemble technique leads to [{(L)Ni}{(4,4‐bpy)Au(PPh3)}2](OTf)4, ( 1,2,3 ) [{(L)Ni(4,4‐bpy)}4](OTf)8, ( 4,5,6 ) [L = dppm/dppe/(PPh3)2 = diphenyl phosphino‐methane, ‐ethane, bis‐triphenylphosphine, OSO2CF3 is the triflate anion]. The maximum molecular peak of the corresponding molecule is observed in the ESI mass spectrum. Ir spectra of the complexes show ‐C=C‐, ‐C=N‐, as well as phosphine stretching. The 1H NMR spectra as well as 31P (1H)NMR suggest solution stereochemistry, proton movement, and phosphorus proton interaction. Considering all the moieties, there are a lot of carbon atoms in the molecule reflected by the 13C NMR spectrum. In the 1H‐1H COSY spectrum of the present complexes and contour peaks in the 1H?13C HMQC spectrum, we assign the solution structure and stereoretentive transformation in each step.  相似文献   

20.
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