Preparation,crystal structure and electrical conductivity of [EDA][Ni(dmit)2]3 (dmit=1,3-dithiole-2-thione-4,5-dithiolate)

The synthesis, conductivity behavior and crystal structure of the ion radical salt [EDA][Ni(dmit)₂]₃ (EDA=2-diethylamino-1,3-dithiolanylium; dmit=1,3-dithiole-2-thione-4,5-dithiolate) are described. The crystal possesses the triclinic system. The structure consists of thick layers of stacked Ni(dmit)₂ entities separated by EDA cations. Short S⋯S interstack distances are observed such that two-dimensional networks of closely spaced Ni(dmit)₂ are formed and reflected in low anisotropy in conductivities measured in the ab plane (σ_a:σ_b: σ_c=1:2:10⁻⁴). The room-temperature four-probe conductivity measured along the longest axis (b axis) is about 0.2 S cm⁻¹. Temperature dependence shows a thermally activated conductivity with activation energy of 0.11 eV.     

A novel material obtained by electropolymerization of polypyrrole doped with [Sn(dmit)3]2−, [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−

The synthesis of a novel material obtained by electropolymerization of a solution of pyrrole and [NEt₄]₂[Sn(dmit)₃] (dmit = 1,3-dithiole-2-thione-4,5-dithiolato) in MeCN is reported. The material was characterized by cyclic voltammetry, UV–vis and FTIR spectroscopy and thermal analysis. Cyclic voltammetry at several scan rates showed that the material has electroactivity and undergoes redox processes associated with the conducting polymer and the anion in the same potential range found for [Sn(dmit)₃]²⁻. The coulombic efficiency (ratio Q_a/Q_c) is close to 1 for all scan rates, indicating that the material is electrically stable at several potential sweeps. The FTIR spectrum showed that the [Sn(dmit)₃]²⁻ anion had been inserted in the polypyrrole backbone. Modifications in the vibrational modes associated with the [Sn(dmit)₃]²⁻ complex anion suggest interaction with the polymer. The Ppy/[Sn(dmit)₃] exhibits good thermal stability which is an important feature for application as a material for devices.     

Preparation and characterization of a polypyrrole hybrid film with [Ni(dmit)2]2−, bis(1,3-dithiole-2-thione-4,5-dithiolate)nickellate(II)

The synthesis of a hybrid material obtained by electropolymerization of a solution of pyrrole and [NEt₄]₂[Ni(dmit)₂] (dmit = 1,3-dithiole-2-thione-4,5-dithiolato) in acetonitrile solution is reported. The material was characterized by cyclic voltammetry, UV–vis and infrared spectroscopies, scanning electron microscopy (SEM), atomic force microscopy (AFM) and thermal gravimetric analysis (TGA). The FTIR spectroscopy showed that the [Ni(dmit)₂]²⁻ anion has been inserted in the polypyrrole framework and was not destroyed or modified during the polymerization process. The voltammetric analysis indicated that the material has electroactivity and undergoes redox processes associated with the conducting polymer and the counteranion. The cyclic voltammetry results also suggest that the counteranion is not trapped in the PPy matrix undergoing anion exchange during the redox cycle of PPy. The PPy/[Ni(dmit)₂]²⁻ exhibits good thermal stability and a intrinsic conductivity value in the range of semiconductors (10⁻³ S cm⁻¹).     

Studies on transition-metal 4,5-dimercapto-1,3-dithiole-2-one (DMID) complexes. Preparation and characterization

A series of integer or non-integer oxidation-state metal complexes of the multi-sulfur donor ligand 4,5-dimercapto-1,3-dithiole-2-one (DMID) with Ni(II), Cu(II) and Zn(II) has been prepared by precipitating them as tetrabutylammonium, tetraethylammonium, or tetramethylammonium salts. The compounds are characterized by negative-ion fast atom bombardment mass spectral analysis, Fourier transform IR spectral analysis and UV-Vis spectral analysis. Synthetic studies reveal that the stoichiometry of the complex depends not only on the nature of the counter cation, but also on the aerial-oxidation time after the addition of the counter cation and on the nature of the central chelating metal ion. The electronic spectral studies of the complexes with those of related compounds reveal that there are strong π-d interactions in the Ni-chelating species. As an important starting material, the synthesis of 1,3,4,6-tetrathiapentalene-2,5-dione is studied in detail as well.     

A novel material based on polyaniline doped with [Cs][In(dmit)2], (cesium) [bis(1,3-dithiole-2-thione-4,5-dithiolato)indium (III)]

A novel conducting hybrid material based on polyaniline doped with a monoanion derived from [cesium][bis(1,3-dithiole-2-thione-4,5-dithiolato)indium(III)], ([Cs][In(dmit)₂]), is reported. Fourier transform infrared (FTIR), UV–vis and X-ray photoelectron spectroscopies showed that the [Cs][In(dmit)₂] acts as the doping agent for the emeraldine base (insulating form of the polyaniline). This new material presents lower resistivity than the starting materials, and forms a flexible, self-supporting film with good homogeneity, which is an important feature for the development of new devices to be useful in the electroelectronic industries.     

Synthesis,crystal structure and electrical conductivity of [bmim][Ni(dmit)2]3 (bmim = 1-butyl-3-methylimidazolium,dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

A new complex [bmim][Ni(dmit)₂]₃ has been prepared, and its crystal structure and electrical conductivity where determined and measured. Crystallographic parameters for C₂₆H₁₅N₂S₃₀Ni₃: triclinic system; space group: P-1; a=12.760(3), b=19.441(4), c=11.670(2) Å; α=102.00(3), β=117.10(3), γ=95.06(3)°; Z=2, R=0.0579 (I>2σ(I)). The conductivity of this salt at room temperature is 1.7×10⁻² S cm⁻¹ and it shows semiconduction in the temperature range of 110–290 K.     

Electrochemical behaviour of the 2-(9H-fluoren-9-yliden)-4,5-dimethyl-1,3-dithiole. Electrochemical behaviour and physicochemical properties of the derived polymer

The synthesis and the anodic oxidation in CH₂Cl₂+0.2 M Bu₄NBF₄ of the title fluorene are described. The electrochemical behaviour and the physicochemical properties of the derived polymer are discussed, as well as the structure of the complex formed between this compound and tetracyanoquinodimethane (TCNQ).     

Crystal structure and physical properties of YbCuZnSb2

The crystal structure of YbCuZnSb₂ has been determined for the first time by single-crystal X-ray diffraction analysis. It is shown that YbCuZnSb₂ has a CaAl₂Si₂-type structure, space group is P-3m1, with the following unit cell parameters: a = 4.4394(1) and c = 7.4139(3) Å. Magnetic susceptibility measurements performed in the temperature range from 2 to 300 K show that ytterbium ions are found in a nonmagnetic 4f ¹⁴ ground state (Yb²⁺). YbCuZnSb₂ exhibits p-type conductivity. The temperature dependence of the resistivity has a metallic character. The variations in the Cu/Zn ratio in the synthesized material occur without any disturbance of the structural type. This fact may confirm the existence of a solid solution between the YbZn₂Sb₂ and YbCuZnSb₂ compounds.     

Preparation and electrical conduction properties of polymeric transition metal complexes of 1,1,2,2-ethenetetrathiolate ligand

The preparation and electrical conduction properties of a series of polymers based on transition metal complexes of the 1,1,2,2,-ethenetetrathiolate ligand (TT) of stoichiometry M₂-TT are described. The nickel, copper and platinum complexes exhibit high electrical conductivities (5, 5 and 3 S cm⁻¹, respectively); the cobalt and palladium polymers have conductivities many orders of magnitude lower. Partial oxidation of the copper-containing polymer can result in a ten-fold increase in the conductivity.     

Crystal structure and physical properties of a magnetic molecular conductor (EDO-TTFVODS)2FeCl4

Crystal structure, and electrical conducting and magnetic properties of a radical cation salt of EDO-TTFVODS with magnetic FeCl₄^? ion, (EDO-TTFVODS)₂FeCl₄ (EDO-TTFVODS = ethylenedioxytetrathiafulvalenoquinone-1,3-diselenolemethide) are reported. In this salt, there are two independent donor molecules formed two different layers A and B, and the counter FeCl₄^? ions layer is sandwiched between two donor layers A and B along the b-axis. The donor molecules form the one-dimensional columns along the a-axis in both donor layers. This salt shows high conductivity at room temperature (σ_RT = 25 S cm^?1) and a metallic behavior down to ca. 80 K, where a metal–insulator transition however occurs. The magnetic susceptibility obeys a Curie–Weiss law (Curie constant C = 4.42 emu K mol^?1 and Weiss temperature Θ = ?1.5 K), without any magnetic ordering down to 1.8 K. This result suggests the weak antiferromagnetic interaction between the d spins of FeCl₄^? ions.     

Synthesis of CETBz-TTF and CESBz-TTF: Preparation, structural and physical properties of their radical salts with paramagnetic Cu(II) complex anions

CETBz-TTF (4,5-bis(cyanoethylthio)benzo-tetrathiafulvalene) and CESBz-TTF (4,5-bis(cyanoethylseleno)benzo-tetrathiafulvalene) 5 have been synthesized from cyano precursor via a cross-coupling reaction. Radical salts with paramagnetic Cu(II) complex anions, such as (CETBz-TTF)₂CuCl₄ 6 and (CESBz-TTF)₂CuCl₄ 7 have been prepared. X-ray crystal structure and physical properties of these new compounds are presented.     

羧酸铑(II)轴向配合物的合成、表征及催化性能

以羧酸铑(II)为母体,吡啶-2-基(吡啶-4-基)甲酮(24ma)为轴向配体,合成了4种新型羧酸铑(Ⅱ)轴向配合物,且成功培养出化合物单晶。使用1H NMR、13C NMR、MS、IR和X-单晶射线衍射对其结构进行表征,讨论了取代基和轴向配体对分子结构的影响,并初步测试了它们对美罗培南类化合物合成反应的催化性能。结果表明,与母体分子羧酸铑(II)相比,所选定的羧酸铑(Ⅱ)轴向配合物因在反应体系中溶解度较差、配体不易解离等原因,导致催化合成美罗培南类化合物的产率不高。     

Two conductive phases of 1,3-dimethylimidazolium-(TCNQ)2 complex salt

Two conductive phases were found by crystallization of the complex ion-radical salt of the 1,3-dimethylimidazolium 7,7′,8,8′-tetracyano1,4-quinodimethane (TCNQ) under different conditions: (i) bulk crystallization from the acetonitrile solution and (ii) crystallization on a glass substrate giving rise to an interconnected fibrous crystal conductive network (σ = 1.7 mS ⁻¹). The electrical conductivity of the latter phase is more than four orders of magnitude higher than that of the former phase. The crystal lattices of both phases are different. The first phase is triclinia (P1) with cell parameters a = 7.811 Å, b = 13.378 Å, c = 7.276 Å, α = 93.152 °, β= 113.739 °, γ = 106.068 °. Indexing of the X-ray diffraction patterns recorded with samples of the latter phase gives a = 13.65 Å, b = 12.70 Å, c = 3.80 Å, γ = 108.3 °; α and β could not be determined.     

Structural study of the highly conductive tridecylmethylammonium-Au(dmit)2 Langmuir-Blodgett films

The structure of the conductive Langmuir-Blodgett (LB) film consisting of tridecylmethylammonium-Au(dmit)₂ (3C10-Au) and arachidic acid is studied by the X-ray diffraction method and atomic force microscopy (AFM). The electrochemically ClO⁻₄-doped film is found to possess four phases with different interlayer spacings by the X-ray diffraction method. The intralayer molecular arrangement is found for the 3C10-Au matrix by AFM.     

Metal complexes of (LH2) ligand: 8,9-bis(hydroxyimino)-4,7,10,13-tetraaza-1,2,15,16-O-dicyclopentylidenehexadecane: Crystal structure,electrical and optical properties

Molecular semiconducting complexes constitute one of the most fascinating, recent research topics, deeply involving both chemists and solid states physicists. Considerable interest has been shown in the synthesis and study of molecular complexes which may behave like semiconducting materials or at least show high conductivities. In this study, structural, electrical and thermal conductivity and optical properties of some inorganic complexes were investigated. From the XRD data, the unit cells of the samples were found as L–Cu is amorphous and L–Ni, L–Co are orthorhombic. L–Cu, L–Ni and L–Co have n-type of electrical conductivity. Electrical and optical band gaps of the complexes were found to be 1.46–1.36, 2.68–2.71 and 1.40–1.32 eV, respectively.     

Preparation and physical properties of polycrystalline (Bi1-xPbx)2Sr2Ca2Cu3Oy highT c superconductors

(Bi_1-xPb_x:)2Sr₂Ca₂Cu₃O_y (x = 0.3) high critical transition temperature (T _c) superconductors are synthesized by the solid-state reaction method in polycrystalline form. X-ray diffraction (XRD) studies, direct current (dc) electrical resistivity measurements, scanning electron microscopic (SEM) studies, critical current density measurements, and zero-field alternating current (ac) susceptibility measurements are performed to investigate the physical changes, structural changes, and magnetic behavior of the superconducting samples. X-ray diffraction studies show that a highT _c phase exists with orthorhombic symmetry in the specimen. According to the XRD data, the lattice parameters of the highT _c phase were determined asa = 0.537(1) nm,b = 0.539(1) nm, andc = 3.70(1) nm. The compound exhibits a superconducting transition at 106 ±1 K for zero resistance. The ac susceptibility measurements in zero field confirm the dc electrical resistivity results; hence both support the XRD results. The particle size and structural changes as a function of the cold-pressing and aging effect are also reported.     

Composition dependence of structure,physical and mechanical properties of FeCoNi(MnAl)x high entropy alloys

This paper has provided a systematic study of the crystal structure, physical and mechanical properties of FeCoNi(MnAl)_x (0 ≤ x ≤ 2) high entropy alloys. As x increases, the crystal structure changes from FCC to FCC + BCC then to BCC solid solution. High saturated magnetization, low coercivity together with high electric resistivity are found in this system, indicating their potential applications as soft magnets. Meanwhile, the strength and hardness increase monotonously as x increases. Optimal balance of physical and mechanical properties are obtained in this system.     

Synthesis, characterization, and electroluminescent properties of iridium complex containing 4-phenybenzoquinoline ligand

A phosphorescent iridium(III) complex Ir(PBQ)₂(acac) (PBQ: 4-phenylbenzoquinoline, acac: acetylacetone) was designed and synthesized, and the single crystal of this complex was obtained. This complex shows well optoelectronic properties. The organic light emitting devices (OLEDs) based on this complex were successfully fabricated with the device configuration of ITO/NPB or TCTA (40 nm)/Ir-complex: CBP (7%, 30 nm)/BCP (15 nm)/Alq (30 nm)/LiF (1 nm)/Al (100 nm). Using TCTA as the hole-transporting material, the device gives an extremely high external quantum efficiency of 14.6% at 5.0 V, a brightness of 61,693 cd/m² at 16.0 V, and a power efficiency of 37.0 lm/W at 3.5 V.