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).     

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.     

New radical salts based on TEMPO-substituted 2,4,6-triphenylpyridinium and transition metal complexes

Series of radical salts derived from a 2,4,6-triphenylpyridinium (TPP) carrying TEMPO-substituent and transition metal complexes were prepared by the anion exchange of the TPP–TEMPO tetrafluoroborate with [n-Bu₄N][Ni(dmit)₂], [n-Bu₄N]₂[Pd(dmit)₂], [n-Bu₄N]₂[Pt(dmit)₂], [n-Bu₄N][Ni(mnt)₂], or [n-Bu₄N]₂[Ni(mnt)₂] to give crystals with different structural features. While weak antiferromagnetic interactions of the Curie–Weiss behavior of S = 1/2 spin are predominantly observed in the salts of Pd(dmit)₂, Pt(dmit)₂ and Ni(mnt)₂, the magnetic behavior of 1:1 Ni(dmit)₂ salt can be explained by the additional contribution from the spins on Ni(dmit)₂ anions (χ − χ_TEMPO), obeying the 2D Heisenberg model. A couple of the oxidized salts, [TPP][Ni(dmit)₂] as well as [TPP]₂[Pd(dmit)₂], exhibit semi-conducting properties with relatively high room temperature conductivities.     

Organoheterobimetallic cyanodithioimidocarbonates and their I2-doped products: Synthesis,characterization and conducting properties

Complexes of the type [PhHg]₂[M(cdc)₂], [Me₂Sn][M(cdc)₂], [n-Bu₂Sn][M(cdc)₂], [n-Bu₃Sn]₂[M(cdc)₂] and [Ph₃Sn]₂[M(cdc)₂] (M = Ni(II) and Cu(II); cdc²⁻ = cyanodithioimidocarbonate) and their I₂-doped products have been prepared and characterized by microanalysis, magnetic and solution as well as solid phase conductivity measurements, IR, Raman, electronic, ¹H and ¹³C NMR and ESR spectroscopic techniques. ESR silent diamagnetic compounds [PhHg]₂[Cu(cdc)₂], [Me₂Sn][Cu(cdc)₂], [n-Bu₂Sn][Cu(cdc)₂], [n-Bu₃Sn]₂[Cu(cdc)₂] and [Ph₃Sn]₂[Cu(cdc)₂] are strongly antiferromagnetically coupled. [PhHg]₂[Ni(cdc)₂] is weakly paramagnetic because of the weak axial interactions of sulfur atoms of the ligand cdc²⁻ with some of the Ni(II) centers. Sharp ¹H NMR signals suggest that [PhHg]₂[Cu(cdc)₂], [n-Bu₂Sn][Cu(cdc)₂], [n-Bu₃Sn]₂[Cu(cdc)₂] and [Ph₃Sn]₂[Cu(cdc)₂] remained diamagnetic in solution as well. Majority of the complexes exhibited σ_rt in the range of 10⁻¹¹ to 10⁻¹⁰ S cm⁻¹ while the I₂-doped products show enhanced conductivity in the 10⁻¹⁰ to 10⁻⁶ S cm⁻¹ range and exhibit semiconducting behaviour.     

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.     

Crystal structure,spectral and electrochemical properties of [TBA]2[Ni(i-MNT)2], [TBA][Ni(i-MNT)2], [TBA]2[Ni(i-MNS)2] and related bis(1,2-dithiolene) metal complexes

The synthesis, crystal structure and physical properties of bis(1,1-dithiolene) or bis (1,1-diselenolene) metal complexes of [TBA]₂[Ni(i-MNT)₂], [TBA][Ni(i-MNT)₂] and [TBA]₂[Ni(i-MNS)₂] (i-MNT = 2,2-dicyanoethylene-1,1-dithiolate,i-MNS = 2, 2-dicyanoethylene-1, 1-diselenolate) were studied and compared to one another or to the related bis (1,2-dithiolene) metal complexes of 5,6-dihydro-1,4-dithiin-2,3-dithiolate, 1,3-dithiole-2-thione-4,5-dithiolate and 1,3-dithiole-2-one-4,5-dithiolate ligands. The structures of the complexes contain equidistant anionic stacks well separated by the counter cation sheets. The planarity and short C-S or C-Se distances in the structures indicate extensive delocalization of the π-system in the compounds. The relative low conductivities for the complexes are due to the low polarizability, large intra-and inter-stack S ··· S distances, and the relative high on-site electron-electron repulsion energy in the compounds.     

Synthesis,crystal structure and electrical properties of [Pd(dmit)2]2− and [Pd(dmit)2]0.5− anion complexes with 2-dimethylamino-1,3-dithiolanylium as counter cation

The synthesis, structural characterization and electrical conductivity measurement of [MDA]₂[Pd(dmit)₂] (1 and [MDA] [Pd(dmit)₂]₂ (2) (MDA = 2-dimethylamino-1,3-dithiolanylium, dmit = 1,3-dithiole-2-thione-4,5-dithiolate) are reported. Complex 1 consists of two Pd(dmit)₂ anions and four MDA cations in the unit cell and the anions are separated by cations in the crystal; the conductivity is about 10⁻⁷ S cm⁻¹. The structure of complex 2 is made of stacked Pd(dmit)₂ dimers. The modes of intra- and inter-dimer molecular overlapping are both of slide-away types. Pd atoms deviate from planes formed by four ligand S atoms 0.07 Å apart to approach each other. Room-temperature conductivity is 10–70 S cm⁻¹. Temperature-dependent conductivity measurement of this compound indicated that it is a semiconductor with a low activation energy (0.043 eV).     

New bisdithiolene metal complex of the 2-thioxo-1,3-dithiole-4,5-dithiolato(dmit) ligand. Preparation,structure and physical properties

The complex HMEDA[Ni(dmit)₂]₂I (HMEDA=Hexamethylethylenediammonium) has been prepared. A single X-ray crystal structure analysis reveals that there are short S⋯S contacts between Ni(dmit)₂ dimmers. The monoclinic system, space group p2/n, has cell dimensions: a=11.710(3) Å, b=22.559(5) Å, c=7.374(2) Å, β=93.000(3)⁰, V=1945.3(8) ų, z=4. Full-matrix least-squares refinement, based on 2989 reflections converged at R=0.0686. The conductivity of this salt at room temperature is 0.1 S cm⁻¹ and it shows semiconducting behavior from 20 to 300 K.     

Synthesis of CeO2/TiO2 nanoparticles by laser ablation of Ti target in cerium (III) nitrate hexahydrate (Ce(NO3)3·6H2O) aqueous solution

A new synthesis process, laser ablation in an aqueous solution of target material, was applied to synthesize nanostructured CeO₂/TiO₂ catalyst particles. Reactivity within the laser plume (plasma) can be used to synthesize CeO₂ from an aqueous solution, 2 M cerium (III) nitrate hexahydrate (Ce(NO₃)₃·6H₂O) aqueous solution, and to fabricate TiO₂ from Ti target. CeO₂/TiO₂ nanoparticles were successfully synthesized by the laser ablation of Ti target in 2 M cerium (III) nitrate hexahydrate (Ce(NO₃)₃·6H₂O) aqueous solution. Laser ablation of Ti in a liquid environment and chemical reactions of the solution within a plasma plume are discussed.     

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.     

Low-dimensional magnetic behaviour of new radical-ion salts: (BEDT-TTF)2[AuIII(i-mnt)2] and (BEDT-TTF)2[BiBr4]

Electrical and magnetic properties of two new radicalion salts of BEDT-TTF (BEDT-TTF is bis(ethylenedithio)-tetrathiafulvalene) are reported. (BEDT-TTF)₂[Au^III(i-mnt)₂] (i-mnt is 1,1-dithio-2,2-dicyano-ethylene) is a semiconductor, σ_r.t. = 2.0 × 10⁻¹−5.5 × 10⁻² S cm⁻¹ with a temperature dependent activation energy (0.14–19 eV). The powder magnetic susceptibility (10–300 K) has been fitted according to a uniform antiferromagnetic (S = 1/2) Heisenberg model by using the experimental g value of 2.0067 and a magnetic exchange constant J/k_B of −110 K. (BEDT-TTF)₂ [BiBr₄] shows similar electrical and magnetic behaviour with σ_r.t. = 5 × 10⁻² S cm⁻¹ on a powdered sample and J/k_B = − 79 K. At low temperature impurities are responsible for the Curie-like behaviour.     

Growth, crystal structure and optical properties of layered dibarium cadmium diborate, Ba2Cd(BO3)2

A novel dibarium cadmium diborate, Ba₂Cd(BO₃)₂, has been successfully synthesized by standard solid-state reaction. Large sheet-like crystal with size up to 20 mm × 15 mm × 0.7 mm has been obtained using top-seed solution growth method. Ba₂Cd(BO₃)₂ crystallizes in the monoclinic space group C2/m with a = 9.6305(4) Å, b = 5.3626(3) Å, c = 6.5236(2) Å, β = 118.079(3)°, Z = 2. The crystal structure is composed of isolated [BO₃] triangles, [CdO₆] octahedra and [BaO₉] polyhedra. CdO₆ are vertex-connected with six BO₃ to form infinite _∞[Cd(BO₃)₂] layers extending in (0 0 1) plane, and two rows of Ba atoms closely occupy two side of _∞[Cd(BO₃)₂] layers to forming stoichiometric sheets. IR and transmittance spectrum of Ba₂Cd(BO₃)₂ were reported.     

Infrared spectroscopic properties of Tm, Ho:NaY(WO4)2 single crystals

Singly doped and Tm³⁺/Ho³⁺ co-doped NaY(WO₄)₂ single crystals were grown successfully by Czochralski method. The room temperature polarized absorption and fluorescence spectra as well as the decay curves were measured. Spectroscopic parameters related to the laser operation around 2.0 μm via the ³F₄ → ³H₆ (Tm³⁺) and ⁵I₇ → ⁵I₈ (Ho³⁺) transitions have been evaluated. The energy level scheme and energy transfer processes of Tm³⁺ and Ho³⁺ were analyzed.     

氨基酸类铱(Ⅲ)配合物的合成、表征及对汞离子的识别

以4-(苯并[d]噻唑-2-基)-N,N-二甲基苯胺(1)、L-丝氨酸作为主配体和辅助配体,合成了一种新型环金属铱配合物(2),所有化合物的结构通过¹H NMR、MS和IR进行了表征确认。通过紫外吸收光谱和荧光发射光谱研究了铱配合物(2)的光物理性质,并采用含时密度泛函理论(TDDFT)对其最低能量电子跃迁和最低三重激发态进行了计算。而且铱配合物(2)的荧光发射光谱可选择性地被汞离子猝灭,暗示着此配合物可作为一种高效的turn-off型汞离子磷光传感器。     

Synthesis and crystal structure of an organic-inorganic complex [Cu（DMF）3（H2O）2]2[SiMo12O40]·2H2O

The synthesis and crystal smacture of an polyoxometalate-based organic-inorganic complex [Cu（DMF）3（H2O）212[SiMo12O40].2H2O （DMF = N, N-dimethyl formamide） is described in this article. It was characterized using elemental analysis, thermal analysis, infrared, ultraviolet, and electron spin resonance spectroscopic studies. The X-ray crystallography analysis showed that the copper centers are pentacoordinated to show the square pyramidal geometry, and the polyanion [SiMo12O40]4- which is semi-coordinated to the copper（I/） centers prevents the existence of a sixth ligand. In addition, the intracationic hydrogen interaction enhanced the stability of the copper coordination cation.     

Intermolecular interactions in the structure of new molecular semiconductor [Pd(dddt)2]2CF3SO3

An X-ray structural investigation of a new molecular semiconductor, [Pd(dddt)₂]₂CF₃SO₃ (1), where dddt²⁻ is 5,6-dihydro-1,4-dithiin-2,3-dithiolate, is made. Crystal data of 1:a = 6.521(7) Å, b = 8.354(4) Å, c = 16.113(6) Å, α = 87.12(4)°, β = 85.51(6)°, γ = 67.94(7)°, V = 811(1) ų, triclinic, space group P. Crystal structure 1 is characterized by layers of [Pd(dddt)₂]^1/2+ radical cations, with [CF₃SO₃]⁻ anions located between them. In these layers, [Pd(dddt)²]^1/2+ cations form dimers with strongly shortened intermolecular contacts Pd…Pd 3.031 (2) Å. The [CF₃SO₃]⁻ anion in the structure of 1 is disordered.     

Polarized spectral analysis of Er ions in Er:LiGd(MoO4)2 crystal

The Er³⁺:LiGd(MoO₄)₂ crystal with Ø21 × 33 mm³ was grown by the Czochralski technique, and the absorption spectra, the fluorescence spectra and the fluorescence decay curves were measured at room temperature. Some spectroscopic parameters, such as the parameters of oscillator strengths, the spontaneous transition probabilities, the fluorescence branching ratios, the radiative lifetimes and the emission cross-sections were estimated based on Judd-Ofelt theory and Füchtbauer-Ladenburg method. The infrared emission at 1450-1650 nm, due to ⁴I_13/2 → ⁴I_15/2 transition and the visible emission at 520-569 nm corresponding to ²H_11/2,⁴S_3/2 → ⁴I_15/2 transition were observed in Er³⁺:LiGd(MoO₄)₂ crystals under 979 nm excitation at room temperature. The emission cross-sections are 4.37 × 10⁻²⁰ cm² at 553 nm and 0.584 × 10⁻²⁰ cm² at 1561 nm for π-polarization, and the following measured lifetimes are 4.57 ms and 10.74 μs. The upconversion emissions were attributed to energy transfer between Er³⁺ ions and the excited state absorption.     

Investigation on temperature dependence of photoluminescence in Sr1.7Eu0.3MxCeO4.15+x/2 (M = Li, Na, K, x = 0, 0.3) red phosphors

The temperature-dependent luminescence of Sr_1.7Eu_0.3M_xCeO_4.15+x/2 (M = Li⁺, Na⁺, K⁺, x = 0, 0.3) samples was investigated and discussed in the temperature range from 303 to 573 K. It is found that the thermal quenching temperature of samples decreases with Li⁺-/Na⁺-doping but increases with the incorporation of K⁺. We suggest that these observations are resulted from two factors. One is that the incorporation of Li⁺/Na⁺/K⁺ ions reduces the strength of potential field at the O²⁻ sites, and then results in a red-shift of the Eu-O charge transfer band. The other is that Δr expands with Li⁺-/Na⁺-doping but shrinks with K⁺-doping. We consider that it is a feasible way to adjust the temperature-dependent luminescence properties of materials by introducing appropriate impurities.     

A study on microstructure and luminescent properties of oxyfluoride silicate glass-ceramics with (Ho,Yb):NaYF4 crystallites

Glass-ceramics containing NaYF₄ nanocrystals were prepared by heat-treatment from oxyfluoride silicate-based glass doped with Ho³⁺ and Yb³⁺ ions. The formation of crystalline fluoride phase was confirmed by X-ray diffraction and transmission electron microscopy. Absorption and emission spectra revealed that a fraction of Ho³⁺ and Yb³⁺ ions is incorporated into the NaYF₄ ordered lattice influencing spectroscopic features of glass-ceramics in comparison with those of precursor glass. Green up-conversion emission (545 nm) originating in the ⁵S₂ level in glass-ceramics and up-converted red emission (650 nm) originating in the ⁵F₅ level in as-melted glass were observed under optical pumping into Yb³⁺ absorption band and analyzed. Although both emissions in both materials are achieved by two-photon excitations, the relation between green and red emission intensity in glass-ceramics and glass implies that processes relevant to up-conversion phenomena are different. Based on a careful analysis of relaxation dynamics of Ho³⁺ and Yb³⁺ excited states, the mechanisms involved in conversion of the infrared radiation into the visible emission in these materials are proposed and discussed.