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1.
We demonstrated efficient red organic light-emitting diodes based on a wide band gap material 9,10-bis(2-naphthyl)anthracene (ADN) doped with 4-(dicyano-methylene)-2-t-butyle-6-(1,1,7,7-tetramethyl-julolidyl-9-enyl)-4H-pyran (DCJTB) as a red dopant and 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10(2-benzothiazolyl)quinolizine-[9,9a,1gh]coumarin (C545T) as an assistant dopant. The typical device structure was glass substrate/ITO/4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA)/N,N′-bis(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB)/[ADN:Alq3]:DCJTB:C545T/Alq3/LiF/Al. It was found that C545T dopant did not by itself emit but did assist the energy transfer from the host (ADN) to the red emitting dopant via cascade energy transfer mechanism. The OLEDs realized by this approach significantly improved the EL efficiency. We achieved a significant improvement regarding saturated red color when a polar co-host emitter (Alq3) was incorporated in the matrix of [ADN:Alq3]. Since ADN possesses a considerable high electron mobility of 3.1 × 10−4 cm2  V−1 s−1, co-host devices with high concentration of ADN (>70%) exhibited low driving voltage and high current efficiency as compared to the devices without ADN. We obtained a device with a current efficiency of 3.6 cd/A, Commission International d’Eclairage coordinates of [0.618, 0.373] and peak λmax = 620 nm at a current density of 20 mA/cm2. This is a promising way of utilizing wide band gap material as the host to make red OLEDs, which will be useful in improving the electroluminescent performance of devices and simplifying the process of fabricating full color OLEDs.  相似文献   

2.
The mono(pyridine-N-oxide) analog of the H4dota macrocylic ligand, H3do3a-pyNO, is capable of forming thermodynamically stable and kinetically inert Ln(III) complexes. Its Eu(III) and Tb(III) complexes display a strong long-lived fluorescence as a result of the antenna effect of the pyridine-N-oxide fluorophore in the reagent. It is shown that H3do3a-pyNO can be used as a fluorogenic reagent for the determination of Eu(III) and Tb(III) at pH 6.5 and cL=1 mM. At an excitation wavelength of 286 nm, the emission maxima are 615 nm (Eu(III)-complex), and 547 nm (Tb(III)complex). Detection limits are at concentrations around 1.0 μM and linearity of the method spans over 2 orders of magnitude. The method was applied to artificial and real samples (spiked mineral waters, extracts from cathode ray tube luminophore dust) and gave satisfactory results. The method is simple, rapid, and hardly interfered by other metal ions.  相似文献   

3.
Five dimethylindium complexes of type Me2InL [L = N-(4-methoxy)benzylidenethiobenzahydrazonato (1), N-(3,4-dimethoxy)benzylidenethiobenzahydrazonato (2), N-(4-N,N-dimethylamino)benzylidenethiobenzahydrazonato (3), N-(2-naphthyl)methylene thiobenzahydrazonato (4) and N-(9-anthryl)methylenethiobenzahydrazonato (5)] have been synthesized by reaction of trimethylindium with appropriate N-arylmethylenethiobenzahydrozones. The complexes obtained have been characterized by elemental analysis, 1H NMR, IR and mass spectroscopy. Compounds 15 emit blue colors at λmax = 432–479 nm when irradiated by UV light. The electroluminescent (EL) properties of 15 were examined by fabricating EL devices using 15 as emitter, respectively. The EL bands are located in the green region (513–578 nm).  相似文献   

4.
The magnetic and structural properties of three gradual spin transition monomeric compounds based on the cation [Fe(Hpt)3]2+ (Hpt=3-(pyrid-2-yl)-1,2,4-triazole) are presented. The non-cooperative character of the spin-crossover in [Fe(Hpt)3](BF4)2·2H2O (I) is evaluated in light of its calorimetric properties, which yielded the thermodynamic values ΔtrsH=5.81 kJ mol−1 and ΔtrsS=39.5 J mol−1 K−1. The light-induced excited spin-state trapping effect is performed on [Fe(Hpt)3](BF4)2·2H2O (I) and [Fe(Hpt)3](SO4)0.4(BF4)1.2·3H2O (II), and the subsequent HS→LS relaxations are studied. Their merely first-order kinetics are affected by disorder in the structure of both complexes, which appears in the presence of a distribution of activation energies. HS species can also be frozen-in in I by rapid cooling. Continuous irradiation is shown to induce only apparent light-induced thermal hysteresis effect in I and II, stemming from slow kinetics of relaxation with respect to the kinetics of measurement.  相似文献   

5.
In our effort to systematically study the far infrared (FIR) spectra of asymmetrically mono deuterated methanol (CH2DOH) and thereby obtain the transition wavenumbers with better and better accuracy (Mukhopadhyay, 2016a,b), the complete Fourier transform (FT) spectra from FIR to infrared (IR) vibrational bands (in the range 50–1190 cm−1) have been re-recorded using the Synchrotron Radiation Source at the Canadian Light Sources in Saskatchewan, Canada. The resolution of the spectrum is unprecedented, reaching beyond the Doppler limited resolution as low as about 0.0008 cm−1 with a signal to noise (S/N) ratio is many fold better than that can be obtained by commercially available FT spectrometer using thermal sources (e.g., Globar). Spectra were also recorded beyond 1190 cm−1 to about 5000 cm−1 at a somewhat lower resolution of 0.002–0.004 cm−1. In this report the analysis of the b-type and c-type torsional - rotational spectra in the ground vibrational state corresponding to gauche- (e1/o1) to gauche- (e1/o1) and gauche- (e1/o1) to trans- (e0) states in the ground vibrational state are reported and an atlas of the wavenumber for about 2500 FIR assigned absorption lines has been prepared. The transitions within a given sub-band are analyzed using state dependent expansion parameters and the Q-branch origins. The data from previous results (Mukhopadhyay, 2016a,b) along with the present work allowed a global analysis yielding a complete set of molecular parameters. The state dependent molecular parameters reproduce the experimental wavenumbers within experimental uncertainty. In addition, the sensitivity of the spectrum allowed observation of forbidden transitions previously unobserved and helped reassignment of rotational angular momentum quantum numbers of some ΔK = ±1, Q-branch transitions in highly excited states recently reported in the literature. To our knowledge the wavenumbers reported in the present work are the most accurate so far reported in the literature and represent the highest resolution spectra for this molecular species.  相似文献   

6.
A novel Aryl amide ligand H2L and its eight complexes, [LnH2L(NO3)2·H2O]NO3 [Ln=Sm(III), Er(III), Tb(III), Dy(III), La(III), Gd(III), Nd(III), and Pr(III)], are presented. The ligand and complexes were synthesized and characterized based on elemental analyses, molar conductance, IR, 1H and 13C-NMR, UV–VIS., and TGA studies. The conductivity data show a 1:1 electrolytic nature with a general formula [LnH2L(NO3)2·2H2O]NO3 The IR spectra reveal coordination of the ligand through the azomethine nitrogen and the phenolic hydroxyl of the ligand to the lanthanide ion. The coordinated nitrate ions behave in a bidentate fashion. The thermal decomposition studies indicate the presence of two water molecules in the inner coordination sphere. Under the excitation at 319 nm, the luminescence emission properties for Sm, Tb, and Dy complexes are observed. These observations show that the ligand favors energy transfers to the emitting energy level of these lanthanide ions. Furthermore, the antioxidant activity of the ligand and its Ln(III) complexes was determined by DPPH radical scavenging method, which indicates that the Ln(III) complexes exhibit more effective antioxidant activity than the ligand alone.  相似文献   

7.
The mass analyzed threshold ionization (MATI) technique has been used for measuring the adiabatic ionization energy of the 3-methylindole·C6H6 cluster (58 018 cm−1) and the binding energies in its ground ionic (4448 cm−1) and ground neutral state (1775 cm−1). We compare our results with those recently obtained for the 3-methylindole·H2O and the indole·C6H6 cluster. The small influence of methylation on the binding energies confirms the πhydrogen bonding character in the 3-methylindole·C6H6 complex.  相似文献   

8.
《Solid State Ionics》2006,177(9-10):885-892
Tri block-copolymer poly(iminoethylene)-b-poly(oxyethylene)-b-poly(iminoethylene) with a poly(oxyethylene) central block (PEI-b-PEO-b-PEI) were used as a “dual” matrix for polymer electrolytes having selectivity for hard cations (Li+/PEO) in one phase and for soft cations (Cu2+/PEI) in the other. Conductivity measurements were recorded for 20:1, 12:1 and 8:1 coordinating atom (O or/and N) to cation (Li+, Cu2+) ratios, for each of the three complexes studied: PEI-b-PEO-LiTFSI-b-PEI, PEI-Cu(TFSI)2-b-PEO-b-PEI-Cu(TFSI)2 and PEI-Cu(TFSI)2-b-PEO-LiTFSI-b-PEI-Cu(TFSI)2. For either low (20 °C) or high temperature (80 °C) the highest conductivity was given by the polymer electrolyte based on Cu(TFSI)2 with N/Cu2+ = 20:1 (10 6, respectively 2 × 10 4 S cm 1). In the present paper, the conductivity evolution is discussed in relation with the polymer structure, the type and the concentration of the salt and the thermal behavior of our systems.  相似文献   

9.
《Solid State Ionics》2006,177(1-2):95-104
The plastic crystal phase forming N-methyl-N-propylpyrrolidinium tetrafluoroborate organic salt (P13BF4) was combined with 2, 5 and 10 wt.% poly(vinyl pyrrolidone) (PVP). The ternary 2 wt.% PVP/2 wt.% LiBF4/P13BF4 was also investigated. Thermal analysis, conductivity, optical thermomicroscopy, and Nuclear Magnetic Resonance (11B, 19F, 1H, 7Li) were used to probe the fundamental transport processes. Both the onset of phase I and the final melting temperature were reduced with increasing additions of PVP. Conductivity in phase I was 2.6 × 10 4 S cm 1 5.2 × 10 4 S cm 1 1.1 × 10 4 S cm 1 and 3.9 × 10 5 S cm 1 for 0, 2, 5 and 10 wt.%PVP/P13BF4, respectively. Doping with 2 wt.% LiBF4 increased the conductivity by up to an order of magnitude in phase II. Further additions of 2 wt.% PVP slightly reduced the conductivity, although it remained higher than for pure P13BF4.  相似文献   

10.
Nanoparticles of a new three-dimensional Mn(II) coordination supramolecular compound, [Mn(L)2(H2O)2] (1), (L = 1H-1,2,4-triazole-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses. Structural determination of compound 1 reveals the Mn(II) ion is six coordinated, bonded to two nitrogen atoms, two oxygen atoms from the L ligand and two water molecules. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA) and compared each other. Concentration of initial reagents effects on size and morphology of nano-structured compound 1, have been studied and shows that low concentrations of initial reagents decreased particles size and also leaded to fibrous-like nanostructures morphology. Mn3O4 nano-structure with an octahedral-like morphology were simply synthesized by solid-state transformation of compound 1 at 650 °C.  相似文献   

11.
Using a sonochemical method, nanoparticles of a new Ce(III) supramolecular compound, (NAMH+)2[Ce4(pydc)6(pydcH)2(H2O)8]·8H2O (1), (H2pydc = 2,6-pyridinedicarboxylic acid, NAM = nicotinamide), have been synthesized. Compound 1 was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses, and its structure was determined by X-ray crystallography. It has been revealed that its structure consists of tetra-nuclear building units that extend to a 3D supramolecular network via non-covalent interactions mainly hydrogen bonding. The thermal stability of complex 1 both for its crystals and nanostructures has been studied by the thermal gravimetric (TG) method and compared with each other. The role of ultrasound irradiation power and the concentration of initial reactants on the size and morphology of the nano-structured complex 1, has been investigated. Ceria nanoparticles were obtained upon the calcination of complex 1 at 800 °C under atmospheric air. Furthermore, the fluorescent properties of complex 1 at room temperature were studied.  相似文献   

12.
《Solid State Ionics》2006,177(26-32):2561-2564
Colloidal monoclinic zirconia ZrO2 particles have been synthesized by hydrothermal treatment from acetate solutions. To increase their surface acidity, they have been treated by aqueous solutions of phosphoric acid, sulfophenylphosphonic acid (SPPA, (HO)2(O)–C6H6–SO3H) and sulfodifluoromethylphosphonic acid (SFPA, (HO)2(O)P–CF2–SO3H). This leads to the covalent bonding of phosphoric or sulfonic acid groups onto the surface of the particles. Solid state NMR (31P, 1H) studies show the covalent grafting of the phosphate and phosphonates groups and qualitatively illustrate the fast proton dynamics of these surface conducting materials as compared with that of crystalline α-Zr(HPO4)2. H2O. But, water adsorption is still necessary to increase the long distance proton mobility. Then, the macroscopic conductivity remains low (between 10 4 S cm 1 and 10 3 S cm 1 25 °C, RH 70%) and shows a strong hysteresis while cycling the relative humidity. The mechanism limiting the conductivity seems to be interparticle transfer.  相似文献   

13.
《Solid State Ionics》2009,180(40):1683-1689
The complex perovskite (Pr0.75Sr0.25)1  xCr0.5Mn0.5O3  δ (PSCM) has been prepared and studied as possible anode material for high-temperature solid oxide fuel cells (SOFCs). PSCM exhibits GdFeO3-type structure and is both physically and chemically compatible with the conventional YSZ electrolyte. The reduction of PSCM resulted in structural change from orthorhombic Pbnm to cubic Pm-3m. Selected area electron diffraction (SAED) analysis on the reduced phases indicated the presence of a √2 × √2 × 2 superlattice. The total conductivity values of ∼ 75% dense Pr0.75Sr0.25Cr0.5Mn0.5O3  δ at 900 °C in air and 5% H2/Ar are 9.6 and 0.14 S cm 1 respectively. The conductivity of PSCM drops with decreasing Po2 and is a p-type conductor at all studied Po2. The average TEC of Pr0.75Sr0.25Cr0.5Mn0.5O3  δ is 9.3 × 10 6 K 1, in the temperature range of 100–900 °C and is close to that of YSZ electrolyte. The anode polarization resistance of PSCM in wet 5%H2 is 1.31 Ω cm2 at 910 °C and in wet CH4 at 930 °C; the polarization resistance is 1.29 Ω cm2. PSCM was unstable at 900 °C in unhumidified hydrogen. Cell performance measurements carried out using graded PSCM and La0.8Sr0.2MnO3 as anode and cathode respectively yielded a maximum power density of 0.18 W cm 2 in wet 5%H2/Ar at 910 °C and the corresponding current density was 0.44 A cm 2 at 0.4 V. The activation energy for the electrochemical cell operating in wet (3% H2O) 5%H2/Ar fuel is 85 kJ mol 1.  相似文献   

14.
《Solid State Ionics》2006,177(26-32):2407-2411
Electrical conduction of Sr-doped LaP3O9 ([Sr]/{[La] + [Sr]} = 2–10 mol%) was investigated under 0.4–5 kPa of p(H2O) and 0.01–100 kPa of p(O2) or 0.3–3 kPa of p(H2) at 573–973 K. Sr-doped LaP3O9 showed apparent H/D isotope effect on conductivity regardless of the Sr-doping level under both H2O/O2 oxidizing and H2/H2O reducing conditions at investigated temperatures. Conductivities of the material were almost independent of p(O2) and p(H2O). These results demonstrated that the Sr-doped LaP3O9 exhibited protonic conduction under wide ranges of p(O2), p(H2O) and temperature. The conductivity of the Sr-doped LaP3O9 increased with increasing Sr concentration up to its solubility limit, ca. 3 mol%, while the further Sr-doping slightly degraded the conductivity. These indicate that Sr2+ substitution for La3+ leads to proton dissolution into the material and induced protonic conduction. Conductivities of the 3 mol% Sr-doped sample were 2 × 10- 6–5 × 10 4 S cm 1 at 573–973 K.  相似文献   

15.
We report the controllable growth of rice-shape nanoparticles of Alq3 by an extremely facile self-assembly approach. Possible mechanisms have been proposed to interpret the formation and controlled process of the single crystal nanoparticles. The field-emission performances (turn-on field 7 V μm−1, maximum current density 2.9 mA cm−2) indicate the potential application on miniaturized nano-optoelectronics devices of Alq3-based. This facile method can potentially be used for the controlled synthesis of other functional complexes and organic nanostructures.  相似文献   

16.
Two novel Ru(II) complexes [(η6-p-cymene)RuCl(L2)]PF6 (R2) and [(η6-C6H6)RuCl(L2)]PF6 (R4), with ligand (E)-N-((6-bromopyridin-2-yl)methylene)-4-(methylthio)aniline (L2), were synthesized and characterized by elemental analysis, 1H NMR, 13C NMR and IR spectroscopy. Based on X-ray crystallography studies, complexes R2 and R4 have coordination environments with formulated (η6-p-cymene)Ru(N2Cl) and (η6-C6H6)Ru(N2Cl), respectively. The thermal stabilities of compounds R2 and R4 were studied by thermal gravimetric (TG) and differential scanning calorimetry (DSC). Thermal decomposition of these complexes was at 280 °C and 260 °C under air atmosphere respectively. The interaction of these complexes with calf thymus DNA (CT-DNA) was explored through electronic absorption spectra, fluorescence and redox behavior studies. The results showed that the complexes bind to CT-DNA with electrostatic interactions. Nanoparticles of RuO2 were prepared by calcination of R2 and R4. Also the role of the ultrasound waves on the characteristics of the RuO2 nanoparticles was studied. The nanoparticles were characterized by IR spectroscopy and X-ray diffraction (XRD). Also size and morphology of nanoparticles were studied by scanning electron microscopy (SEM).  相似文献   

17.
《Current Applied Physics》2010,10(4):1071-1075
The physical and electrochemical properties of the activated carbon pellet electrodes have been investigated. Activated carbon pellets were prepared from single step carbonization process of pre-carbonized rubber wood sawdust at a temperature of 800 °C that followed with a CO2 activation process at temperature in the range of 700–1000 °C. The BET characterization on the sample found that the surface area of the carbon pellet increased with the increasing of the activation temperature. The optimum value was as high as 683.63 m2 g−1. The electrical conductivity was also found to increase linearly with the increasing of the activation temperature, namely from 0.0075 S cm−1 to 0.0687 S cm−1 for the activation temperature in the range of 700–1000 °C. The cyclic voltammetry characterization of the samples in aqueous solution of 1 M H2SO4 also found that the specific capacitance increased with the increasing of the activation temperature. Typical optimum value was shown by the sample activated at 900 °C with the specific capacitance was as high as 33.74 F g−1 (scan rate 1 mV s−1). The retained ratio was as high as 32.72%. The activated carbon pellet prepared from the rubber wood sawdust may found used in supercapacitor applications.  相似文献   

18.
《Solid State Ionics》2006,177(11-12):1091-1097
The effects of compositions on properties of PEO/KI/I2 salts polymer electrolytes were investigated to optimize the photovoltaic performance of solid state DSSCs. XRD pattern for the mole ratio 12:1 of [EO:KI] was showed the formation of complete amorphous complex. DSC results also confirmed the amorphous nature of the polymer electrolyte. The highest value of ionic conductivity is 8.36 × 10 5 S/cm at 303 K (ambient temperature) and 2.32 × 10 4 S/cm at 333 K (moderate temperature) for the mole ratio 12:1 of EO:KI complex. The effect of contribution of [I] and [I3] concentration with conductivity were also evaluated. FTIR spectrum reveals that the alkali metal cations were co-ordinated to ether oxygen of PEO. The formation of polyiodide ions, such as symmetric I3 (114 cm 1) and I5 (145 cm 1) caused by the addition of iodine was confirmed by FT Raman spectroscopic measurements. The optimum composition of PEO–KI–I2 polymer electrolyte system for higher conductivity at ambient and moderate temperatures was reported. A linear Arrhenius type behaviour was observed for all the PEO–KI polymer complexes. Transport number measurements were carried out for several polymer electrolyte compositions. Dye-sensitized solar cells were fabricated by using higher conductivity polymer electrolyte compositions and its photoelectrochemical performance was investigated. The fill factor, short-circuit current, photovoltage and energy conversion efficiency of the DSSC assembled with optimized electrolyte composition were calculated to be 0.563, 6.124 mA/cm2, 593 mV and 2.044% respectively.  相似文献   

19.
《Journal of Molecular Liquids》2006,123(2-3):105-109
It is shown that the conductivities of LiBF4, LiPF6, LiN(SO2CF3)2 (LiTFSI), NaPF6, KPF are abnormally high in two diamine solvents: ethylenediamine (EDA) and 1,3-diaminopropane (1,3 DAP). This is particularly evident for KPF6, κMAX(EDA) = 35 mS cm 1 and κMAX(1,3 DAP) = 17.4 mS cm 1. Compared to three other organic solvents having the same viscosity, η  1.6 cP, but higher relative permittivity, NMF ε = 186.9, NMP ε = 32, γ-Bu ε = 39.1, the maxima of conductibility of EDA and 1,2 DAP, which have a low relative permittivity, ε  13–11, are largely superior or equal to those of NMF, NMP, γ-Bu. For KPF6, κMAX(NMF) = 15.4mS cm 1, κMAX(NMP) = 7.8 mS cm 1 and κMAX(γ-BL) = 10.8 mS cm 1. We assume that this is due to a non-Stokesian conductivity mechanism.  相似文献   

20.
《Current Applied Physics》2010,10(3):904-909
An electrosynthesis process of hydrophilic polyaniline nanofiber electrode for electrochemical supercapacitor is described. The TGA–DTA study showed polyaniline thermally stable up to 323 K. Polyaniline nanofibers exhibit amorphous nature as confirmed from XRD study. Smooth interconnected fibers having diameter between 120–125 nm and length typically ranges between 400–500 nm observed from SEM and TEM analysis. Contact angle measurement indicated hydrophilic nature of polyaniline fibers. Optical study revealed the presence of direct band gap with energy 2.52 eV. The Hall effect measurement showed room temperature resistivity ∼3 × 10−4 Ω cm and Hall mobility 549.35 cm−2V−1 s−1. The supercapacitive performance of nanofibrous polyaniline film tested in 1 M H2SO4 electrolyte and showed highest specific capacitance of 861 F g−1 at the voltage scan rate of 10 mV/s.  相似文献   

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