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1.
以含有共轭大π键的2,5-双(乙炔基二茂铁)噻吩(BFET)和二甲基双十八烷基铵(DMDOA)与Keggin结构和Dawson结构钨磷杂多酸做成膜材料, 用LB技术组装了两种新型无机-有机杂化LB膜. 用π-A曲线、UV-vis吸收光谱、原子力显微镜(AFM)、扫描隧道显微镜(STM)、荧光光谱和表面光电压谱(SPS)对标题LB膜的成膜性能、结构及光电性质进行了研究, 发现标题杂化LB膜的粒子具有纳米尺寸, 在可见光区有较强的光电压响应, 在电压为±2.0 V时, 隧道电流值达到±100 nA.  相似文献   

2.
A new family of organometallic/inorganic nanohybrid Langmuir-Blodgett (LB) films consisting of rigid-rod organomercury acetylide complex (OMA) as the π-conjugated organometallic composite and heteropolyacid salts MPA (MPA = K3PMo12O40, K5BW12O40, Na5IMo6O62) of the Keggin and Anderson structures as the inorganic composite, were prepared and characterized by π−A isotherms, UV−Vis absorption spectra, fluorescence spectra, scanning tunneling microscopy, atomic force microscopy imaging and low-angle X-ray diffraction. Our experimental results indicate that steady Langmuir and LB films are formed in pure water and heteropolyacid salt subphases. Luminescence spectra of hybrid LB films show that MPA can quench the emission of OMA to some extent. These alkynylmercury(II) based LB films display interesting electrical conductivity behavior. They all show decent electrical conductivity, and the tunneling current amounts to ±100 nA when the voltage is set at ±3 ∼ ±5 V.  相似文献   

3.
以含有共轭大π键的对叔丁基杯[8]芳烃(Cal8)和十八(烷)铵(ODA)与Keggin结构和Dawson结构钼磷杂多酸(HPA)做成膜材料, 用LB技术制备了2种新型无机-有机杂化LB膜. 用π-A曲线、UV-Vis吸收光谱、荧光光谱和原子力显微镜(AFM)对标题LB膜的成膜性质、结构及发光性质进行了表征. 结果表明在空气/水界面Cal8/ODA/HPA杂化可形成稳定的单层与多层膜. 标题杂化LB膜的崩溃压为39.0 mN/m, 其粒子具有纳米尺寸, 在激发波长为280 nm时, 可观察到322~387 nm处由Cal8分子π-π*跃迁引起的荧光发射峰及510 nm处 杂多阴离子的配体到金属的荷移跃迁(LMCT)三重发射谱带.  相似文献   

4.
有机金属聚合物/多酸纳米杂化LB膜的制备与光电性质研究   总被引:1,自引:0,他引:1  
以含有共轭大π键的有机金属聚合物(OMP)作有机组分, 以Keggin结构和Dawson结构钨(钼)磷杂多酸作无机组分, 以十八胺为辅助成膜剂, 用LB技术制备了3种新型有机金属聚合物/十八铵/杂多阴离子OMP/ODA/HPA (HPA=PMo12, PW12, P2Mo18)杂化LB膜. 用π-A曲线﹑UV-vis吸收光谱﹑荧光光谱﹑原子力显微镜(AFM)﹑扫描隧道显微镜(STM)和表面光电压谱(SPS)对标题LB膜的成膜性能及光电性质进行了研究, 结果表明标题杂化LB膜的崩溃压为26.8 mN/m, 在可见光区有较强的光电压响应, 并有好的发光性质. 当电压为±8.0 V时, 隧道电流是-0.1~-2.3 nA.  相似文献   

5.
A new family of organometallic/inorganic composite Langmuir‐Blodgett (LB) films consisting of rigid‐rod polyplatinayne polymer ([Pt‐T(OMe‐Fl)T] or [Pt‐T(F‐Fl)T], where the triplet bonds are abbreviated by T, and fluorene ring by Fl) as the π‐conjugated organometallic molecule, polyoxometalate (POM, POM = K3PMo12O40, H3PW12O40, or H6P2W18O62) of the Keggin and Dawson structures as the inorganic component, and dimethyldioctadecylammonium bromide (DODA) or a mixture of octadecanoic acid (OA) and docosanoic acid (DA) as the auxiliary film‐forming agent were prepared and characterized by π–A isotherms, UV–Vis absorption spectra, photoluminescence spectra, atomic force microscopy imaging, scanning tunneling microscopy, and low‐angle X‐ray diffraction. Our experimental results indicate that steady, even, and ordered Langmuir and LB films are formed in pure water and polyoxometalate subphases. It was shown that the POM molecules are probably embedded inside the polyplatinayne molecules in the LB film structure and they can quench the luminescence of the Pt polyyne. These Pt‐polyyne based LB films display interesting electric conductivity behavior. [Pt‐T(OMe‐Fl)T]/DODA/HPW12 monolayer film shows a good electrical conductivity, and the tunneling current amounts to ±100 nA when the voltage is set at ±8 V. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3193–3206, 2008  相似文献   

6.
采用界面吸附法制备了5种十八/杂多阴离子杂化LB膜ODA/HPA(HPA=PW12,PMo12,MPo12,PW6Mo6,PW9Mo3,P2Mo18).对5种本合物在空气/水界面上单分子膜的行为进行了研究,它们有较高的崩溃压46.0-48.0mN,m^-1,均能开稳定的单分子膜,用红外光谱,紫外光谱,小角X射线衍射(LXRD)和荧光光谱对LB膜的沉积特性与结构进行了鉴定,结果表明,制备的LB膜具有中心对称性,其层状结构由杂多阴离子的单层与表面活性剂双层交替组成。  相似文献   

7.
A new series of organometallic/inorganic composite Langmuir‐Blodgett (LB) films consisting of a rigid‐rod polyplatinyne polymer coordinated with 2,7‐bis(buta‐1,3‐diynyl)‐9,9‐dihexylfluorene (denoted as PtP) as the π‐conjugated organometallic molecule, an europium‐substituted polyoxometalate (POM; POM = Na9EuW10O36, K13[Eu(SiW11O39)2] and K5[Eu(SiW11O39)(H2O)2]) as the inorganic component, and an amphiphilic behenic acid (BA) as the auxiliary film‐forming agent were prepared. Structural and photophysical characterization of these LB films were achieved by π–A isotherms, absorption and photoluminescence spectra, atomic force microscopy imaging, scanning tunneling microscopy, and low‐angle X‐ray diffraction. Our experimental results indicate that stable, well‐defined, and well‐organized Langmuir and LB films are formed in pure water and POM subphases, and the presence of Eu‐based POM in the subphase causes an area expansion. It is proposed that a lamellar layered structure exists for the PtP/BA/POM LB film in which the POM and PtP molecules can lay down with the interfacial planes. Luminescence spectra of the prepared hybrid LB films show that near‐white emission spectra can be obtained due to the dual‐emissive nature of the mixed PtP/POM blends. These Pt‐polyyne‐based LB films displayed interesting electric conductivity behavior. Among them, PtP/BA/POM 13‐layer films showed a good electrical response, with the tunneling current up to ±100 nA when the voltage was monitored between ?1 and 7 V. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 879–888, 2010  相似文献   

8.
A novel organic–inorganic hybrid polyoxoniobate K8Na2{[Cu(en)(H2O)]2 [HNb6O19]2}·25H2O (en = ethylenediamine) 1 has been synthesized by the diffusion method and structurally characterized by elemental analyses, IR, UV-Vis spectra, thermogravimetric (TG) analysis and single crystal X-ray diffraction. The structure analysis indicates that 1 consists of two {[Cu(en)(H2O)][HNb6O19]}5− polyoxoanions linked each other by two methane-like {K4Na}5+ cationic clusters. Surface photovoltage spectroscopy (SPS) and electric field induced surface photovoltage spectroscopy (EFISPS) measurements indicate that 1 is the n-type conduction characteristic. In situ UV and CV studies indicate that 1 can stably exist in the larger pH ranges in aqueous solution.  相似文献   

9.
Two new inorganic-organic salts, formulated as (C6H13N5OH)2 [HPMo12O40] · 5H2O and (C6H13N5OH)3[PW12O40], were synthesized and characterized by elemental analysis, IR, ESR, diffuse reflectance spectra, thermogravimetry, and X-ray photoelectron spectroscopy. Solid diffuse reflectance spectra showed charge-transfer interactions between the inorganic and organic moieties in the solid state. Salt I had strong photosensitivity for UV light or X-ray irradiation, and its photochromic reaction under UV light was found to exhibit first-order kinetics. The article is published in the original.  相似文献   

10.
《Electroanalysis》2005,17(7):579-587
Organic/inorganic hybrid films of poly(new fuchsin) and phosphomolybdate (PMo12O ) have been prepared in acidic aqueous solutions. These new combination films are stable, electrochemically active, and can be produced on glassy carbon, platinum, gold, and transparent semiconductor tin oxide electrodes. An electrochemical quartz crystal microbalance along with cyclic voltammetry and UV‐visible absorption spectroscopy were used to study the in situ growth of the hybrid films. The hybrid poly(new fuchsin) and PMo12O films showed four obvious redox couples, and when transferred to various acidic aqueous solutions, the formal potentials of the four redox couples were found to be pH dependent. The electrocatalytic reduction of ClO , BrO , IO , SO , S2O , H2O2, and NO by the hybrid poly(new fuchsin) and PMo12O films was achieved in acidic aqueous solutions. In an aqueous solution at pH 1.5, a hybrid poly(new fuchsin) and PMo12O film showed a higher electrocatalytic reduction activity of IO than BrO or ClO , and the order of electrocatalytic activity was IO >BrO >ClO . The order of electrocatalytic reduction of SO , S2O , H2O2, and NO by hybrid poly(new fuchsin) and PMo12O films in an aqueous solution at pH 1.5 was NO >H2O2>S2O and SO . The electrocatalytic reactions of the poly(new fuchsin) and PMo12O films were investigated using the rotating ring‐disk electrode method.  相似文献   

11.
制备了三种新型双窗长链烷基稀土杂多酸化合物langmuir和langmuir-blodgett膜:DODA/Ln(PW~1~1)~2(Ln=La,Sm,Eu)。用π-A等温线,IR,UV,小角X射线衍射,荧光光谱,光电压谱对其进行了表征。结果表明:它们在空气-水界面有良好的成膜性能,这些单层在表面压为零时,表观单分子占有面积为0.45~0.50nm^2。LB膜有良好的层间有序性,稀土杂多酸阴离子是作为一无机层夹在两个双长链烷基层之间。DODA/Ln(PW)~1~1)~2LB膜具有Sm,Eu的特征荧光,其光电压谱亦有较强的光电响应。  相似文献   

12.
Four Fe(II/III) supramolecules, {[Fe(Hpdc)2(H2O)2]·2H2O} (1), [Fe(HImbc)2(H2O)2] (2), [Fe(phen)2(CN)2]·CH3CH2OH·2H2O (3), K[Fe(tp)2]·SO4 (4) (H2pdc = 2,5-Pyridinedicarboxylic acid, H2Imbc = 4,5-Imidazoledicarboxylic acid, phen = 1,10-phenanthroline, tp = poly(pyrazolyl)borate), were synthesized by hydrothermal and room temperature stirring methods. They were characterized by single crystal X-ray diffraction, surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), electron paramagnetic resonance (EPR), UV–Vis absorption spectra (UV–Vis), infrared spectra (IR) and element analysis. The structural analyses indicate that complex (1) is a supramolecule with 2D structure connected by hydrogen bonds. Complex (2) is a supramolecule with hydrogen-bonded 3D structure. Complexes (3) and (4) are both 1D supramolecules connected by hydrogen bonds. The electronic state of central metal Fe(II) ions in complexes (1) and (2) is d6 with FeN2O4 coordination mode, lying in weaker distorted octahedral field. The electronic state of Fe(II) ion in complex (3) is d6 with Fe(CN)2N4 mode in the strong distorted octahedral field. The electronic state of Fe(III) ion in complex (4) is d5 with FeN6 mode, lying in the strong octahedral field. The micro-environment of Fe(II/III) ions in the four complexes is further investigated by EPR. The SPS of four complexes all exhibit photovoltage responses in the range of 300–700 nm. This indicates that they all possess certain photoelectric conversion capability. The effects of component, structure, type of ligands of the complexes, valence state and coordination micro-environment of the central metal ions on the SPS were discussed. Furthermore, the SPS and UV–Vis absorption spectra were interrelated.  相似文献   

13.
H3PW12O40 heteropoly acid (HPW12) and its Co, Fe, Ni salts supported on alumina have been used to model hydrodesulfurization catalysts of different activity. All catalysts revealed a promoting effect of the countercation in thiophene hydrodesulfurization, that of the nickel cation being the highest. The catalysts were characterized by measurements of surface area, HDS activity, TPR, FTIR, and DR spectra. IR spectra confirmed an effect of the countercation on the phase composition of the supported heteropoly compounds. 12-Tungstoaluminate heteropoly anions and coordinately unsaturated anions of HPW12 were detected in the IR spectra of the catalysts. The hydrotreating activity of the catalysts was proportional to the amount of hydrogen consumed in the range 20–500°C during TPR.  相似文献   

14.
By employing electrostatic interaction as driving force, an organic/inorganic composite with positively charged dimethyl dialkyl‐chain ammonium surfactants encapsulating negatively charged (NH4)12[Mo36(NO)4O108(H2O)16]. 33H2O polyoxoanion was prepared. The structure of the novel organic/inorganic hybrid particle with hydrophilic core and hydrophobic shell in a defined stoichiometric ratio was confirmed by element analysis, 1H NMR and FT‐IR spectra. The property of the polyoxoanion was changed due to the encapsulation and it can be dissolved in organic solvent such as chloroform, benzene and toluene, but not dissolved in water.  相似文献   

15.
Radiochromic films composed of polymer matrices and organic dyes are widely used for routine dosimetry purposes in operation of various radiation facilities—gamma and X-ray-irradiation, electron accelerators, and so on. However, the sensitivity of these films rapidly decreases at doses exceeding 30–50 kGy due to a saturation of their optical response, making them unsuitable for accurate dosimetry in radiation processing of polymers and composites where doses up to 200 kGy are typically employed. To overcome this limitation, the use of inorganic substances as the coloring agents of polymer-based radiochromic films was proposed in this paper, specifically, heteropolyacidacid H3PW12O40 (tungstophosphoric acid) in the matrix of poly(vinyl alcohol) (PVA). Nanocomposite PVA/H3PW12O40 films were prepared by solution casting and their optical responses toward 60Co gamma radiation and beams of 6 MeV electrons for a dose range of 10–200 kGy were investigated. It was established that upon exposure to gamma rays and electron beams, the films turn blue and a broad absorption band at 750 nm appears in their spectra. Importantly, the radiation-induced optical absorption increases in a linear fashion up to the dose of 150 kGy and only slightly deviates from linearity at 200 kGy. Moreover, it was found that the PVA/H3PW12O40 films have a long shelf life, are dose-rate independent within a wide range, and color-stable after irradiation. All these features make the nanocomposite PVA/H3PW12O40 films promising for use as routine dosimeters and dose labels in a much wider range of high doses as compared to radiochromic films based on organic dyes.  相似文献   

16.
稀土三酞菁夹心化合物混合LB膜的研究   总被引:3,自引:0,他引:3  
将不对称三明治型夹心化合物(Pc)Dy[Pc(OC8H17)8]Dy[Pc(OC8H17)8]与硬脂酸混合成膜,表面压-面积(π-A)曲线表明形成了稳定的单层膜,由透射电子显微镜(TEM)观察,表明硬脂酸的加入有效地改善了分子的聚集行为,分子形成了取向高度有序的结构。用紫外-可见光谱、偏振紫外可见光谱、低角X射线衍射等对LB膜进行了研究,发现该取代稀土三酞菁分子在气/液界面上长链向上伸展,分子之间均以面对面(face-to-face)排列,以一边接触(edge-on)方式取向,大环平面与基片夹角约为52°,每层厚度为2.41 nm。  相似文献   

17.
首次选用聚乙烯咔唑(PVK)、二十二烷酸(BA)与杂多阴离子用LB技术制备 了五种有机/无机杂化LB膜,PVK/BA/HPC(HPC = Na_5(PZ(H_2O)Mo_(11)O_(39)]· 5H_2O, Z = Mn, Co, Cu, Zn, Ni)。用原子力显微镜(AFM),UV-vis,小角X射 线衍射(LAXRD),表面光电压谱(SPS),荧光光谱等对LB膜的结构与性质进行了 表征。结果表明:它们在空气/水界面有好的成膜性能,崩溃压为22 ~27 mN/m, 杂多阴离子作为一个单层夹在PVK和BA双层之间。PVK/BA/HPC LB膜的光致发光具有 PVK激基缔合物的特征荧光,其光电压谱有较强的光电响应。  相似文献   

18.
A chiral Schiff base complex, bis(N-R-1-phenylethyl-3,5-dichlorosalicydenaminato) cobalt(II) was prepared newly and characterized to be a distorted tetrahedral trans-[CoN2O2] coordination geometry. Organic/inorganic hybrid materials containing the related cobalt(II), nickel(II), copper(II), and zinc(II) complexes and photochromic azobenzene in polymethylmethacrylate (PMMA) cast films were assembled for comparison of their flexibility and molecular arrangement in the photofunctional medium. Characterization of each component and hybrid materials was carried out by means of absorption and CD spectra and thermal analysis (TG–DTA and DSC). Moreover, we have attempted to observe changes of conformation and/or molecular arrangement of the complexes or azobenzene induced by cistrans photoisomerization of azobenzene after alternate irradiation of polarized UV and visible light. Gradual increase of optical anisotropy was observed for all the hybrid materials regardless of flexibility of Schiff base complexes, and the degree of dichroism and weak intermolecular interactions were discussed based on polarized absorption electronic spectra.  相似文献   

19.
《Vibrational Spectroscopy》2004,34(1):169-173
The monolayer of the mixture of octadecanoic acid and octadecylamine with molar ratio 1:1 has been investigated at the air–water interface. It was found that the monolayer shows a rather stable state at the surface pressure of 30 mN/m and this monolayer can be transferred onto a CaF2 plate by Langmuir–Blodgett (LB) technique. The infrared spectra of LB films indicated that octadecylammonium octadecanoate is formed by an intermolecular proton exchange between adjacent carboxylic and aminic groups (COO and NH3+). In three-layer LB film, the CH2 scissoring mode of the long hydrocarbon chains of octadecylammonium octadecanoate shows a broad band feature at about 1468 cm−1 while this vibrational mode of three-layer LB film of the mixture (1:1) of deuterated stearic acid and octadecylamine (octadecylammonium octadecanoate-d35, C18H37NH3+C17D35COO) only shows a narrow band. The broad feature of the CH2 scissoring mode in octadecylammonium octadecanoate probably originates from the coupling between the chain of stearic acid and that of octadecylamine while this kind of coupling could be completely removed in octadecylammonium octadecanoate-d35. Another conclusion presented in this paper is that there are no couplings among the chains of fatty acid or among the chains of octadecylamine in LB films of octadecylammonium octadecanoate.  相似文献   

20.

Synthesis and characterization, including data on thermal decomposition, are reported for the complexes of S,S'-methylenebis(cysteine) (djenkolic acid) with copper(II), zinc(II) and cadmium(II): CuC7H12N2O4S2 [I]; ZnC7H12N2O4S2 [II] and CdC7H12N2O4S2 [III]. X-ray diffraction showed that the compounds are isostructural and belong to a monoclinic system. According to IR spectra, COO, NH2 groups and bridging sulfur atoms are the main coordination sites.  相似文献   

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