Photoelectric, nonlinear optical, and photorefractive properties of polymer composites based on supramolecular ensembles of Ru(II) and Ga(III) complexes with tetra-15-crown-5-phthalocyanine

Techniques of the production of polymer nanocomposites based on tetrapyrrole compounds with photoelectric, nonlinear optical, and photorefractive properties are considered. Supramolecular ensembles of Ru(II) and Ga(III) complexes with tetra-15-crown-5-phthalocyanine are found to form upon the deposition of thin films from tetrachloroethane solutions that have undergone several cycles of heating followed by slow cooling. The surface formation of supramolecular ensembles is studied with the use of atomic force microscopy. The assemblage is found to give rise to photoelectric and photorefractive sensitivity in the near-infrared range (measurements were carried out at 1064 and 1550 nm). The quantum yield of thermalized electron-hole pairs at 1064 nm in composites of polyvinyl carbazole and assembled Ga(III) complexes is 20 times as high as that in composites based on Ru(II) complexes. The largest two-beam coupling gain coefficient at 1064 nm (Γ = 120 cm^?1 at E ₀ = 120 V/μm) was also observed for the Ga(III)-complex-containing composite. The third-order dielectric molecular susceptibility measured in tetrachloroethane solutions of the complexes weakly depends on the nature of the central atom and its axial neighborhood and falls in a range of γ = 4?5.2 × 10^?32 esu.     

Gold(I) and gold(III) complexes with anionic oxygen donor ligands: hydroxo, oxo and alkoxo complexes

The chemistry of gold(I) and gold(III) hydroxo, oxo and alkoxo complexes containing organic co-ligands is reviewed. Due to the high reactivity of the gold-oxygen bond most of these species can be employed as useful intermediates in many important processes. Alkoxides are by far the most numerous class among these species, and both gold(I) and gold(III) complexes are known with a variety of alkoxides. The recent discovery of the catalytic activity of some gold(I) and gold(III) fluoroalkoxides has enlivened the interest towards this class of compounds leading to new applications for previously known complexes, as is the case for a gold(III) siloxo complex which has found use as a precursor for CVD, as well as for the synthesis of new alkoxo derivatives. Another well represented and well known class of compounds are the gold(I) oxo complexes [O(AuPR₃)₃]⁺ which are the most effective aurating reagents. Gold(III) oxo complexes have been synthesized only recently and much of their chemistry is still largely to be explored. Preliminary studies suggest their potential in the transfer of oxygen atoms. Finally, some cationic gold(III) hydroxo complexes are found to display significant,and in some cases relevant, cytotoxic effects on cancer cell lines.     

Substituted tetra-2,3-pyrazinoporphyrazinino copper(II) complexes: synthesis and nonlinear optical refractive and absorptive properties

Tetra-substituted tetra-2,3-[5,6-(9,10-phenanthro)pyrazino]porphyrazinino copper(II) complexes (AzaPhc, 5a–d) have been prepared via complexation of mono-substituted 5,6- (9,10-phenanthro)-2,3-dicyanopyrazines with copper(I) chloride. Their nonlinear optical properties have been studied by the Z-scan measurements at 532 nm. We found that their effective nonlinear refractive indices n₂^eff (ranging from −4.6×10⁻¹⁰ to −10.0×10⁻¹⁰ e.s.u.) are about two to four times larger than the octa-substituted phthalocyaninine complex, and their triplet excited-state absorption cross sections σ_ex^τ (ranging from 8.2×10⁻¹⁹ to 9.8×10⁻¹⁹ cm²) are about an order less than the phthalocyanine compound. The one-photon excitation and the heating effect have been applied to interpret our experimental results.     

Complexes of zinc(II) tetra-(15-crown-5)-phthalocyaninate with axially coordinates N-donor ligands as potential components of photosensitive materials of telecommunication range

The methods of electron absorption spectroscopy and ¹H NMR were used to study the processes of interactions between zinc tetra-(15-crown-5)-phthalocyaninate and a number of N-donor ligands, including 1,4-diazabicyclo[2.2.2]octane, 4-dimethylaminopyridine, 3-aminopyridine, imidazole, 2-amino-5-methylpyridine, 2-methyla-4-aminopyridine, 2,3-diaminopyridine, pyrazine. A new effective method for synthesizing zinc tetra-15-crown-5-phthalocyaninate was developed that allowed one to obtain the complex at a yield of greater than 80% under simple conditions in 2 h. The structure of associates was studied in detail using the example of interactions between zinc tetra-15-crown-5-phthalocyaninate and 1,4-diazabicyclo[2.2.2]octane. ¹H NMR studies in a wide temperature range of 213–323 K (−60 to +50°C), as well as quantum-chemical calculations, allowed us to establish the formation of two types of associates of phthalocyanine and 1,4-diazabicyclo[2.2.2]octane with the composition of 1: 1 and 2: 1. Up to a temperature of 253 K, the 1: 1 and 2: 1 associates are in equilibrium with a high rate of interconversion.     

The template synthesis and characterization of new mono- and dinuclear Schiff base complexes of lanthanide(III) ions

As a result of [1+2] Schiff base condensation in reaction between 2,6-diacetylpyridine and 3,6-dioxaoctane-1,8-diamine in the presence of lanthanide(III) ions (Ln=La³⁺, Pr³⁺, Nd³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺), the new mono- and dinuclear architectures containing ligand with N₅O₄ set of donor atoms with terminal amine groups were formed. The complexes were clear on the basis of the spectroscopic and thermogravimetric data and microanalyses.     

Photorefractive polymer composites based on ruthenium (II) tetra-15-crown-5-phthalocyanate axially coordinating ethylisonicotinate molecules photosensitive in telecommunication range

Polyvinylcarbazole layers containing ruthenium (II) tetra-15-crown-5-phthalocyanate axially coordinating ethylisonicotinate molecules are found to have photoelectric and photorefractive sensitivity at 1550 nm. The effect is determined by the formation of supramolecular ensembles with the electronic optical absorption and photoelectric sensitivity in the near IR range up to 1600 or 1700 nm and nonlinear optical properties. A photorefractive two-beam coupling gain coefficient Γ measured at 1550 nm increases with an increase in the Ru(II) complex content in the polymer layer and equals 25 cm⁻¹ at 6 wt %. The difference between the coupling gain and absorption coefficients (the actual gain coefficient) is Γ − α = 19 cm⁻¹. Additionally introducing 3 wt % C₆₀ fullerene into the layer does not change the characteristics, but the subsequent preirradiation (irradiation of the whole layer with a 633-nm laser beam in a range of the optical absorption of C₆₀ before recording photorefractive curves) results in an increase in the gain coefficient at 1550 nm up to Γ = 48.3 cm⁻¹ and, hence, in Γ − α = 42.3 cm⁻¹. A time constant of the diffraction grating formation is about τ = 0.8 s.     

Linear analysis on the stability of lanthanide vapor complexes LnAl3Cli2(Ln = La to Lu)

The reactions LnCl3 (s) + (3/2)Al2Cl6 (g) = LnAl3Cl12 (g) for Ln = La to Lu were studied by quenching experi-ments in roughly the same temperature and pressure ranges (588-851 K and 0.01-0.22 MPa). Stability constants Kθ oflanthanide complexes LnAl3Cl12 were calculated from the measurements. The values of lg Kθ change linearly with theionpotential (Z+/r) of lanthanide(Ⅲ) from La to Gd and from Tb to Lu, respectively, indicating the Gd break. There exist in-clined W effect between lg Kθ and the total angular momentum L of lanthanide(Ⅲ). And hereby lanthanide elements aredivided into four segments, La-Nd, Pm-Gd, Tb-Ho, and Er-Lu. In each segment, the linearity is maintained.     

Perdeuterio bis(ethylenedithio)tetrathiafulvalene

The deuterated S-based organic donor molecule bis(ethylenedithio)-tetrathiafulvalene 5b, C₁₀S₈D₈, was synthesized with high deuterium purity (99.7+%) by phosphite coupling of the thione intermediate perdeuterio-4,5-ethylenedithio-1,3-dithiole-2-thione 3b, C₅S₅D₄, or the carbonyl intermediate perdeuterio-2,5,7,9-tetrathiabicyclo [4.3.0] non-1(6)-en-8-on 4b, C₅S₄-OD₄. 3b was prepared by the addition of D₄-ethylenedibromide to an alcoholic solution of 1,3-dithole-2-thione-4,5-dithiolate that was generated by the reaction of sodium with carbon disulfide in N,N-dimethylformamide. No deuterium exchange with solvents during the course of reactions was observed. Compounds 3b-5b, and their isotopic purity, were established by use of mass, NMR, FT-IR and UV-visible spectrometry.     

Physicochemical properties of solutions and ultrathin films of triple-decker gadolinium tetra-15-crown-5-phthalocyaninate

The ability of the triple-decker gadolinium complex with tetra-15-crown-5-phthalocyanine Gd₂(R₄Pc)₃, (R = 15-crown-5) (1) to form monolayers and Langmuir-Blodgett films (LBFs) was studied for the first time. The charge characteristics of molecules of a triple-decker phthalocyaninate in monolayer, as well as their orientation and adhesion to the water subphase, were controlled by changing the surface pressure, pH, and subphase composition (aqueous solutions containing triethylenetetramine (TETA) and metal cations). It was shown that the presence of Na⁺ and protonated TETA aminogroups in resulted in an increasing limiting monolayer area and significant decreasing of the monolayer liquid state region. It is proven that the observed effects are caused by the conformational and charge transitions of peripheral crown ethers induced by their interaction with cations. A comparison of the differential reflectance spectra of the complex monolayer on the deionized water surface with UV-Vis absorption spectra of three-layer Gd₂(R₄Pc)₃ LBF and complex solution in chloroform shows that partial complex oxidation and intensive stacking formation occurs already at the stage of monolayer formation on the subphase surface. Electrochemical studies of three-layer LBFs performed at the indium-tin-oxide electrodes (ITO-electrodes) using cyclic voltammetry (CV) showed three reversible redox waves in the potential range −200 to +1100 mV (vs. Ag⁺/AgCl). All registered peaks remain the same position and intensity upon multiple cycling. plasmon resonance (SPR) measurements allow to register three stable redox states of studied LBF upon applying the external potential. Such behavior shows the possibility to use multistep redox transformations of studied complex LBF for developing of stable and reproducible switchable optoelectronic systems.     

Short communication Linear analysis on the stability of lanthanide vapor complexes LnAl_3Cl_(12)(Ln=LatoLu)

The reactions LnCl3 (s) + (3/2)Al2Cl6, (g) = LnAl3Cl12 (g) for Ln = La to Lu were studied by quenching experiments in roughly the same temperature and pressure ranges (588-851 K and 0.01-0.22 MPa). Stability constants Kθ of lanthanide complexes LnAl3Cl12 were calculated from the measurements. The values of Ig Kθ change linearly with the ionpotential (Z+/r) of lanthanide(Ⅲ) from La to Gd and from Tb to Lu, respectively, indicating the Gd break. There exist inclined W effect between Ig Kθ and the total angular momentum L of lanthanide(Ⅲ). And hereby lanthanide elements are divided into four segments, La-Nd, Pm-Gd, Tb-Ho, and Er-Lu. In each segment, the linearity is maintained.     

Synthesis and electrical conductivities of charge-transfer complexes of bis(vinylenedithio)tetrathiafulvalene and its methyl derivatives with strong acceptors

Charge-transfer complexes of bis(vinylenedithio)tetrathiafulvalene (VT), bis(methylvinylenedithio)tetrathiafulvalene (DMVT) or bis(dimethylvinylenedithio)t tetrathiafulvalene (TMVT) with several strong acceptors, such as TCNQ, F₄TCNQ, DDQ, TCNE, Bu₄NBr₃ and I₂, were synthesized by leaving the mixed solution of a donor and an acceptor to stand at ambient temperature. Not only the usual 1:1 (donor:acceptor) complexes but also 2:1, 1:2, 3:1, 3:2 and 5:2 ones were obtained. Unfortunately, a single crystal of good quality was not obtained. The electrical conductivities of the compressed pellet samples were measured by van der Pauw's method. Most of them showed high conductivities of 10⁰–10⁻¹ S cm⁻¹ at room temperature. However, the TCNQ complexes were insulators. The electrical conductivities could be explained on the basis of the i.r. spectra of the complexes and the redox potentials of the donor and acceptor molecules.     

Synthesis and characterization of lanthanide trifluoroacetate complexes with 3-picoline-N-oxide

Complexes with composition Ln(F₃C-COO)₃·2(3-picNO)·ξH₂O were synthesized. According to X-ray powder patterns and IR data five series of isomorphous compounds were detected: La---Nd; Sm---Eu; Gd>Tm, Y; Ho, Er, Tb; Dy, Yb, Lu. They behave as nonelectrolytes in methanol. IR spectra show a shift of νNO to lower frequencies, as compared with the free ligand, as a result of coordination through the oxygen. The bands attributed to the anions indicate two modes of coordination. The neodymium spectrum at 77 K shows that the central ion is not involved in a cubic site. Electrostatic bonds between Nd³⁺ and ligands were evidenced by the nephelauxetic, Sinha's parameters and covalent factor from the room temperature spectrum. Using the electronic emission spectrum, at 77 K, it was possible to conclude that europium ions present two different symmetry sites, since a splitting of the ⁵D₀ → ⁷F₉ band was observed. The complex species are probably polymeric or at least dimeric, and europium ions are involved in two different sites, but with the same C_3ν symmetry.     

Optical study on bis(propylenedithio)tetrathiafulvalenium (BPDT-TTF) salts

Polarized reflectance spectra of (BPDT-TTF)₃(PF₆)₂ and (BPDT-TTF)₂I₃ were measured at room temperature over the spectral region from 720 cm⁻¹ to 25 000 cm⁻¹. Both of these salts exhibited one-dimensional behaviour in contrast to the BEDT-TTF (bis-(ethylenedithio)tetrathiafulvalenium) salts. The transfer integrals and the on-site Coulomb energy of these materials were estimated by analysing the optical spectra, and the on-site Coulomb energy of (BPDT-TTF)₃(PF₆)₂ was found to be significantly larger than that of TCNQ salts.     

Studies on the interaction between lanthanide ions and ligands, in solid complexes of lanthanide hexacyanometalates. Part II. The kinetics of thermal dehydration of lanthanide hexacyanocobaltate (III) hydrates, Ln[Co(CN)6]·nH2O and yttrium hexacyanocobaltate (III) tetrahydrates

Series complexes of lanthanide hexacyanocobaltates (III), Ln[Co(CN)₆]·nH₂O (Ln=lanthanide ions; n=5,4) and yttrium hexacyanocobaltates (III) tetrahydrate were prepared, and the kinetics of the thermal dehydrations of these hydrates was studied. The dehydrations of Ln[Co(CN)₆]·5H₂O (Ln=La to Nd) took place through at least three stages, and those of Ln[Co(CN)₆]·4H₂O (Ln=Ce to Lu, and Y) through at least two stages. The each dehydration stage was found to be described as a first order reaction, F₁. Activation energy for each stage was determined on the basis of thermogravimetry. The relationship between the activation energy for the each dehydration stages and the thermal stability of the series hydrates which was changing with the decrease of the ionic radii of lanthanide ions, was discussed.     

Photoluminescence and electroluminescence properties of poly(9-vinylcarbarzole) doped with anthracence derivatives containing bis(ethynylphenyl oxadiazole) or bis(vinylphenyl oxadiazole) substituents

The photoluminescence (PL) and electroluminescence (EL) properties of two novel light-emitting anthracence derivatives containing bis(ethynylphenyl oxadiazole) or bis(vinylphenyl oxadiazole) substituents (ANOs) blended with poly(9-vinylcarbazole) (PVK) are characterized. The energy transfer process in the blends is discussed. By employing 2,5-bis(5-tert-butyl-2-benzoxazolyl) thiophene (BBOT) and tris(8-hydroxyquinoline) aluminum (Alq3) as electron transporting layers (ETLs) in the EL devices, remarkable improvements in EL efficiency were observed. The effect of the transporting layer on the EL intensity of the devices is also discussed.     

Solid state photoluminescence of novel lanthanide complexes based on 4-benzoylpyrazolone Schiff base

A novel, promising ligand for luminescent lanthanide complexes tris-((4-(3-methyl-1-phenyl-5-pyrazolonyl)-phenylmethylidene)-2-aminoethyl)amine (trenPMBP) was prepared and used as effective “antenna” for the ligand-sensitized photoluminescence of Tb³⁺, Dy³⁺ and Sm³⁺ ions. All the complexes show surprisingly intensive photoluminescence in comparison with their simple 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone analogues. One of the reasons of such result can be a relatively high located triplet energy level of trenPMBP around 22675 cm^?1, which properly fits with the emissive energy levels of Tb³⁺ and Dy³⁺ (20430 cm^?1 and 20830 cm^?1, respectively), thus avoiding back-energy transfer from the lanthanide to the ligand.     

Cation-promoted supramolecular assembly of bivalent metal tetra-15-crown-5-phthalocyaninates: Controlling the architecture of supramolecular aggregates

Cation-promoted supramolecular assembly of cobalt(II) and ruthenium(II) tetra-15-crown-5-phthalocyaninates is comparatively studied using the electronic absorption and infrared spectroscopy. The effects of the nature of the receptor and substrate on the architecture of the supramolecular aggregates formed are discovered. By contrast to Cu(II), Zn(II), and Ni(II) tetra-15-crown-5-phthalocyaninates, Co(II) and Ru(II) complexes are found to demonstrate sodium-potassium selectivity determined by the peculiarities of supramolecular structures formed upon the interaction with the cations.     

机械合金化法制备的Mn15Bi34Te51和La15Bi34Te51热电材料

用机械合金化法制备了Mn15Bi34Te51和La15Bi34Te51合金，XRD分析表明Mn15Bi34Te51和La15Bi34Te51分别在真空球磨150h和100h后实现合金化，La15Bi34Te51在真空球磨150h后形成了纳米结构的合金，镧原子的加入有助于Bi2Te3基合金的晶粒细化及非晶化。对La15Bi34Te51合金的XRD结构分析表明镧原子有可能进入了Bi2Te3层状结构的Te-Te原子层间。La15Bi34Te51合金Seebeck系数的测量表明当晶粒尺寸减小到纳米尺寸时，载流子散射机制有可能发生改变，导致了Seebeck系数的大幅上升。     

Anodic dissolution of a metal accompanied by the formation of unstable anionic complexes

Transport processes that take place during the anodic dissolution of a metal accompanied by the formation of negatively charged intermediate particles are theoretically considered. Distributions of the component concentrations and electric potential in the diffusion layer during the quasi-equilibrium decomposition of intermediate particles are calculated. Analysis predicts the existence of the admissible concentration limit of anions depending on the stability constant of intermediate particles. The effect of the stability constant on the potential distribution within the diffusion layer and on the shape of voltammetric curves of the process is found to be complex.     

Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

The heteropoly complexes K12[Ln(GeW9Mo2O39)2] · nH2O (Ln = La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis, infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis. IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropoly complexes is a square antiprism consisting of eight oxygen atoms of two GeW9Mo2O398-, heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower than that of saturated Keggin structure dodecatungstogermanate.