A paddlewheel dinuclear Cu(II) compound coordinated with TTF-py redox ligand

A new paddlewheel dinuclear complex with a pyridyl-tetrathiafulvalene (TTF-py) ligand has been obtained and characterized crystallographically as [(DMT-TTF-py)₂Cu₂(OAc)₄]·2C₆H₆ (1). Meanwhile a mononuclear compound [(DMT-TTF-py)₂Cu(PhCOO)₂(CH₃OH)₂]·2CH₂Cl₂ (2) was also isolated. UV–vis spectra and cyclic voltammogram of the paddlewheel complex were studied, showing that compound 1 can undergo an oxidization to form a stable cation of [(DMT-TTF-py)₂Cu₂(OAc)₄]²⁺. By this strategy, compound 3, [(DMT-TTF-py)₂Cu₂(OAc)₄](I₃)₂ as a radical salt, has been prepared and its conductivity of powder sample was 1.02 × 10^?3 ohm^?1 cm^?1. Antiferromagnetic coupling of Cu(II)–Cu(II) was found from the results of ESR spectra, but the coupling between the radical–Cu(II) was very weak.     

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.     

Heteroleptic triple-decker terbium(III) (porphyrinato)(crownphthalocyaninate) as an efficient receptor of alkaline metal cations

Peculiarities of the interaction between a heteroleptic triple-decker terbium(III) complex of a general type [Br₄TPP]Tb[(15C5)₄Pc]Tb[(15C5)₄Pc] (Tb-TD*, where Br₄TPP = 5,10,15,20-tetra-(4-bromophenyl)-porphyrin and (15C5)₄ Pc = tetra-(15-crown-5)-phthalocyanine) and potassium cations in different solvents are studied. The interaction between Tb-TD* and potassium acetate is found to proceed via either the supramolecular dimerization of the complex or the inclusion of the cations between the crown-containing molecular decks depending on the polarity of the media. From the analysis of the titration curves, the stability constant of Tb-TD* × 4K⁺ adduct in a chloroform : methanol = 1 : 1 mixture was estimated. The stability constant of the aggregate was found to exceed the known values of similar compounds by over ten orders.     

Supramolecular assembly of sandwich-type heteroleptic lanthanum (porphyrinato)(phthalocyaninates)

Concentration and cation-induced supramolecular assembly of heteroleptic double- and triple-decker [An₄P]La[(15C5)₄Pc] and [An₄P]La[(15C5)₄Pc]La[An₄P] lanthanum complexes (An₄P²⁻ = 5,10,15,20-tetra-(4-methoxyphenyl)-porphyrinate dianion and(15C5)₄Pc²⁻ = tetra-(15-crown-5)-phthalocyaninate dianion) is studied. Double-decker [An₄P]La[(15C5)₄Pc] complex is shown to be susceptible to effective concentration-driven assembly determined by the deviation from the Beer-Lambert-Bouguer law up to a concentration of 10⁻⁶ M. Triple-decker [An₄P]La[(15C5)₄Pc]La[An₄P] complex is not inclined to the concentration-driven assembly up to a concentration of 10⁻⁴ M. The interaction between the receptors and sodium or potassium salt is determined by the receptor structure and independent of the salt anion. When interacting with potassium salts, the double-decker complex can form a supramolecular cofacial dimer. In the case of the triple-decker complex, the crown-phthalocyanine deck of the molecule is sterically blocked, and supramolecular aggregates do not form. Sodium cations can be encapsulated in the crown ether rings of both receptors.     

Electrically conductive,processable polymeric materials constructed from metallophthalocyanines

This contribution describes an approach to producing new classes of macromolecular/macromolecular and molecular/macromolecular hybrid materials which can be spun into environmentally stable, flexible, oriented, electrically conductive fibers. Solutions of a phthalocyanine-containing macromolecular (e.g., [Si(Pc)O]_n) or molecular(e.g., Ni(Pc)) ‘metal’ precursor and a host polymer (e.g., Kevlar) are wet-spun to yield, after halogen or electrochemical doping, strong, air-stable fibers with thermally activated electronic conductivities as high as 5 ω^?1 cm^?1. X-ray diffraction and resonance Raman studies of the fibers reveal the presence of preferentially oriented Kevlar and {[Si(Pc)O]I_1.1}_n (or M(Pc)I) crystalline regions, the latter regions with the metallophthalocyanine stacking directions preferentially parallel to the longitudinal fiber axis.     

Potassium-promoted anionic selectivity of lanthanide bis(tetra-15-crown-phthalocyaninate) complexes

The interaction between neutral, lanthanide bis(tetra-15-crown-5-phthalocyaninate) complexes Ln[(15C5)₄Pc]₂⁰, (Ln = La, Tb, and Tm) and potassium bromide, picrate, or tetraphenylborate in chloro-form-acetonitrile solutions is studied using the spectrophotometric titration. The architecture of the supramolecular aggregates formed is shown to depend on the size of the lanthanide ion introduced into crown-phthalocyaninate and the nature of potassium salt anion.     

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.     

Formation, fast oxidation and thermodynamic data of Fe(II) hydroxychlorides

Iron(II) hydroxide and hydroxychloride precipitates were obtained by mixing FeCl₂ · 4H₂O and NaOH aqueous solutions with various concentration ratios R′ = [Cl⁻]/[OH⁻] = 2 [FeCl₂]/[NaOH] at [NaOH] = 0.4 mol L⁻¹. They were analysed by Infrared spectroscopy after 24 h of ageing at room temperature. Fe(OH)₂ was obtained alone only for the smallest values of R′, typically R′ ? 1.16. β-Fe₂(OH)₃Cl formed as soon as R′ ? 1.40 and was obtained alone for R′ ? 2.25. The initial precipitates were oxidised by addition of a small amount of hydrogen peroxide (5 mL of an aqueous solution containing approximately 30 vol% H₂O₂) instead of O₂. The action of H₂O₂ on Fe(OH)₂ gave rise to δ-FeOOH as already reported. Its action on Fe(II) hydroxychlorides gave rise to akaganéite β-FeO_1−2x(OH)_1+xCl_x. A transformation of the two-phase system found at R′ = 1.5 after long ageing times (6 months) was observed and β-Fe₂(OH)₃Cl remained alone. This slow transformation of Fe(OH)₂ into β-Fe₂(OH)₃Cl may explain why β-Fe₂(OH)₃Cl was only reported as a corrosion product on iron archaeological artefacts. Finally, the respective domains of stability of Fe(OH)₂ and β-Fe₂(OH)₃Cl were demarcated and an estimation of the standard Gibbs free energy of formation of β-Fe₂(OH)₃Cl could be given: .     

Photo-induced magnetization in copper(II) octacyanomolybdate(IV)

The photomagnetic effect of the mixed-valence compound Cu₂^II[Mo^IV(CN)₈]·7.6H₂O (Cu^II; 3d⁹, S=1/2, Mo^IV; 4d², S=0) (1) was investigated. The UV–VIS spectra showed the intervalence transfer (IT) band between Mo^IV–CN–Cu^II and Mo^V–CN–Cu^I around 500 nm. When the paramagnetic compound 1 was irradiated by a filtered blue light (400–430 nm, 3 mW/cm²) of a Xe lamp at 5 K, the irradiated sample exhibited a spontaneous magnetization with a Curie temperature of 17 K. By annealing the irradiated sample above 200 K, the magnetic property of this sample returned to the initial state. This photo-induced magnetization is explained by the following mechanism. The excitation of the IT band causes the electron transfer from Mo^IV (S=0) to Cu^II (S=1/2), producing a mixed-valence isomer of Mo^V (S=1/2)–CN–Cu^I (S=0). However, half of the copper ions remain as Cu^II ions due to the stoichiometric limitation and hence the irradiated 1 is expressed as Cu^ICu^II[Mo^V(CN)₈]·7.6H₂O. The unpaired electrons on Mo^V (S=1/2) ions and those on Cu^II (S=1/2) ions in the irradiated compound interact ferromagnetically, giving rise to the spontaneous magnetization.     

Multiferroic and magnetoelectric properties of single-phase Bi0.85La0.1Ho0.05FeO3 ceramics

Single-phase Bi_0.85La_0.1Ho_0.05FeO₃ multiferroic ceramics were prepared by a rapid liquid sintering method. The ceramics exhibited an obvious ferroelectric loop with a remnant polarization of 11.2 μC/cm² and also showed weak ferromagnetism with the remnant magnetization of 0.179 emu/g at room temperature. A considerable enhancement of the polarization on magnetic poling and a dielectric anomaly in the vicinity of the antiferromagnetic transition temperature due to the intrinsic magnetoelectric coupling effect were observed in Bi_0.85La_0.1Ho_0.05FeO₃ ceramics. The dielectric constant for the Bi_0.8La_0.1Ho_0.05FeO₃ samples at room temperature decreases with increasing applied magnetic fields, and the coupling coefficient (?′(H) − ?′(0))/?′(0) reaches −1.04% at H = 10 kOe.     

Octa- and tetra-(benzo-15-crown-5)phthalocyanines in surfactant-containing solutions

The behavior of octa-(benzo-15-crown-5)phthalocyanine (H₂cr₈Pc), as well as cobalt octa- and tetra-(benzo-15-crown-5)phthalocyaninates (Cocr₈Pc and Cocr₄Pc), in aqueous solutions containing cationic or anionic surfactants, such as cetyl trimethylammonium bromide (CTAB), sodium carboxymethyl cellulose (Na-CMC), and sodium dodecyl sulfate (SDS), is studied using electronic spectroscopy. The presence of eight benzo-15-crown-5 ether fragments on the periphery of the phthalocyanine ring is shown to facilitate the dissolution of Pc in an aqueous environment. The interactions between CTAB and crown-containing Pc promotes the dissolution of H₂cr₈Pc; Cocr₈Pc; and, to a lesser degree, Cocr₄Pc, which is accompanied by the appearance of molecular aggregates, including heteronuclear cofacial dimers. The presence of a metal in the ring is not the necessary condition of the process. In microscopically heterogeneous medium, such as an aqueous SDS-containing solution, H₂cr₈Pc is present in monomeric form at SDS concentrations close to C _cr and in dimeric form at SDS content below C _cr. Under similar conditions (environment, surfactant), Cocr₄Pc can exist in monomeric form at SDS concentrations much high than C _cr. The effect of the size of cation on the form of the crown-containing Pc in an aqueous solution is illustrated by an example of H₂cr₈Pc. Na-CMC promotes the dissolution of Pc and enables one to produce K⁺/Mcr₈Pc-modified films from aqueous solutions.     

Solubilization of Crown-Substituted Magnesium Phthalocyaninates in Solutions of Salts of Bile Acids

Crown-containing Pc Mg[(B15C5O)₈Pc], Mg[(B15C5O)₄Pc], and Mg[(15C5)₄Pc] are in the monomolecular state in solutions of synthetic anionic surfactants: sodium dodecylsulfate and sodium dodecylbenzenesulfonate. In micellar solutions of bile-acid salts, molecular organization of crown-substituted Pc with different methods of introduction of crown groups into the macrocycle and their different numbers changes their state from predominantly monomeric for Mg[(B15C5O)₈Pc] in the presence of NaCl to the aggregated one in the case of Mg[(15C₅)₄Pc)]. Magnesium phthalocyaninate with annulated (15-crown-5)-fragments, Mg[(15C₅)₄Pc], is characterized by the highest sensitivity to the structure of the micelle-forming biocompatible surfactant.     

The use of cement kiln dust for the removal of heavy metal ions from aqueous solutions

Abstract

The possibility of removal and utilisation of heavy metal (HM) ions from aqueous solutions by cement kiln dust (CKD) has been studied. The experiments have shown that CKD may be used for industrial wastewater decontamination. They revealed that CKD may be used for neutralisation of acidic wastewaters (alkalinity 12–16 meq g^?1) and for removal of HM ions such as Cu(II), Ni(II), Pb(II), Cd(II) and Co(II). CKD acts as an alkaline agent and sorbent. The main crystalline components of CKD are: calcite, CaCO₃ (80% by mass), 10–15% SiO₂ and the remainder is basic calcium silicate, Ca₅(SiO₄)₂(OH)₂. The maximal capacity of CKD to remove Cu(II) is 0·29 g g^?1 CKD (9·1 meq g?1); Ni(II), 0·14 g g^?1 CKD (4·7 meq g^?1); Pb(II), 2·0 g g^?1 CKD (19 meq g^?1); Cd(II), 0·42 g g^?1 CKD (7·4 meq g^?1); and Co(II), 0·20 g g^?1 CKD (6·8 meq g^?1). Interaction of CKD with Cu(II) ions produces devillite Cu₄(CaSO₄)₂(OH)₆·3H₂O, with Pb(II) – basic carbonate Pb₃(CO₃)₂(OH)₂ and with Cd(II) ions – Cd(OH)Cl. The products of interaction of CKD with Ni(II) and Co(II) ions are amorphous: apparently hydrated Ni(OH)₂ and Co(OH)₂.     

Investigations in the field of synthetic metals. VI. Synthesis and properties of dibenzotetrathiafulvalene halides

Direct oxidation of dibenzotetrathiafulvalene (DBTTF) by halogens in acetonitrile and nitrobenzene yielded DBTTF₂I₃, DBTTF·I₃, DBTTF·Cl_x (x = 0.7 ? 1), DBTTF·Br_x (x = 0.8 ? 1), and DBTTF·Br_1.2 complexes. Ir-, u.v.-, and e.p.r.-spectra of these compounds have been studied. X-ray data for the complex DBTTF·I₃ are discussed. Conductivities of the above mentioned complexes lie in the range 10^?2 – 10^?4 ohm^?1 cm^?1.     

New Hybrid Materials Based on Nanostructured Aluminum Oxyhydroxide and Terbium(III) Bis(Tetra-15-Crown-5-Phthalocyaninate)

A new method was developed for preparation of hybrid functional nanostructures through interaction between terbium complex with tetra-15-crown-5-phthalocyanine Tb[(15C₅)₄Pc]₂ and the surface of highly porous nanostructured aluminum oxyhydroxids (NAOs). It was shown that immobilization of phthalocyaninate on an NAO surface may be reversible upon a sorption from the solution in chloroform, and irreversable, when the adsorption occurred on the NAO surface that was chemically modified using methyltrimethoxysilane and annealed at the temperature ranging from 500 to 1100°С (NAOM). Nanostructure and chemical properties of the obtained hybrid nanomaterials were studied with the use of different methods: scanning electron microscopy, XRD, IR and diffuse reflectance spectroscopy. The sensor properties of the obtained Tb[(15C₅)₄Pc]₂//NAO and Tb[(15C₅)₄Pc]₂//NAOM hybrid nanostructures were studied when they interacted with ammonia and iodine vapors. It was shown that the phthalocyaninate complex on the NAO surface was liable to reduction, while the phthalocyaninate complex on the modified NAOM surface was liable to oxidation.     

5′-(Anthracene-9,10-diyl)bis(ethyne-2,1-diyl)bis(2-hexylthiophene) derivatives bearing 5-ethynyl-5′-hexyl-2,2′-bithiophene and 2-ethynyl-5-hexylthieno[3,2-b]thiophene: Thin film transistors and photovoltaic applications

Novel 5,5′-(anthracene-9,10-diyl)bis(ethyne-2,1-diyl)bis(2-hexylthiophene)-based conjugated molecules have been synthesized via the Sonogashira coupling reaction. Newly synthesized anthracene-based molecules exhibit good solubility in common organic solvents and good self-film-forming properties. The semiconducting properties of the two molecules were evaluated in organic thin film transistors (OTFTs). The two π-conjugated molecules 4 and 7 exhibit fairly high charge carrier mobilities—as high as 0.010–0.022 cm² V^?1 s^?1 (I_on/I_off > 10³)—without any annealing process. The high charge carrier mobilities of the as-spun films are attributed to the fact that the molecules demonstrated pronounced J-aggregation behavior, resulting in easy crystallization and dense coverage of the surface of a dielectric layer. In addition, two molecules were employed to fabricate organic photovoltaic (OPV) cells with methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PC₆₁BM) without thermal annealing. As a result, the photovoltaic cell containing 7 had the best preliminary results with an open-circuit voltage of 0.92 V, a short-circuit current density of 1.82 mA/cm², and a fill factor of 0.32, offering an overall power conversion efficiency (PCE) of 0.54%.     

Tetra(9,10-phenanthro)tetraazaporphyrin - phthalocyanine: Comparative electrical conductivities

Tetra(9,10-phenanthro)tetraazaporphyrin, H₂TPTAP, has been synthesized and characterized for comparative electrical conductivity measurements with phthalocyanine, H₂Pc, before and after iodine doping. The objective is to determine the effect on conductivity of fusing eight additional benzo rings to the periphery of the phthalocyanine ring. H₂Pc doped to a (H₂Pc)I_2.5 composition with a resistivity decreases from 10¹⁵ to 1 ω cm, while H₂TPTAP doped to a (H₂TPTAP)I_0.26 composition with a corresponding resistivity change from 10¹¹ to 10⁸ ω cm. Experimental data and the literature indicate that benzene rings fused to the periphery of the tetraazaporphyrin ring have little π-electron interaction. Similarly, the structure-conductivity correlation of data is interpreted as indicating that fusion of additional benzo rings has an insulating substituent group effect on oxidation of and charge transport between the tetraazaporphyrin rings in the polycrystalline solid.     

9,10-Bis(phenylethynyl)anthracene-based organic semiconducting molecules for annealing-free thin film transistors

New anthracene-containing conjugated molecules have been synthesized through Stille coupling reaction. 2,6-Dibromoanthracene-9,10-dione was reacted with ethynylbenzene or 1-ethynyl-4-hexylbenzene to yield 2,6-dibromo-9,10-bis(phenylethynyl)anthracene 4 and 2,6-dibromo-9,10-bis((4-hexylphenyl) ethynyl)anthracene 5. Tributyl(5-hexylthiophen-2-yl)stannane was coupled through Stille reaction to generate two anthracene-based X-shaped molecules. They exhibit good solubility in common organic solvents and good self-film-forming properties. The semiconducting properties of the two molecules were evaluated in organic thin film transistors (OTFTs). Two conjugated molecules 7 and 8 exhibit fairly high charge carrier mobilities—as high as 0.010–0.014 cm² V^?1 s^?1 (I_on/I_off = 1.27 × 10⁷ to 4.38 × 10⁶) without thermal annealing process. The X-shaped molecules result in easy crystallization and densely cover the surface of a dielectric layer. This helps in attaining good network interconnection for the carrier transport channel, which is responsible for the relatively high carrier mobility in solution-processed OTFT.     

Ein dem Malachit ähnliches basisches Eisenkarbonat als Korrosionsprodukt von Stahl

A basic ferrous carbonate similar to malachite as a corrosionproduct of steel A formerly unknown basic ferrous carbonate is described, which was found on the cone of a hot water valve (temperature 180°C) together with siderite and magnetite. According to analysis the formula is Fe_1,8²⁺Fe_0,2²⁺(OH)_2,2CO₃ or “Fe₂(OH)₂CO₃” with some amorphous ferric oxidehydrate. The unit cell of said compound is orthorhombic: a = 9,39₀Å; b = 24,53 Å; c = 3,21₂ Å; Z = 8 aspect p* ab. The measured density: 3,59 g · cm^?3. An infrared spectrum was taken and the frequencies of absorption coordinated tentatively with vibrations between 800–500 cm^?1. Thermal analysis in oxygen leads to a stepwise exothermic decomposition and oxidation in course of which above 197°C an intermediate metastable compound (ferric oxidecarbonate “Fe₂O₂CO₃”) is topotactically formed. The unit cell of this compound is orthorhombic: a = 9.23 Å; b = 12,18 Å; c = 5,94 Å. Also in this case an infrared spectrum was taken and bonds coordinated. Above 360°C further decomposition leads the formation of hematite. Decomposition in argon starts at 300°C. The reaction is endothermic and the product magnetite. A structural relationship exists between “Fe₂(OH)₂CO₃” and malachite and also to siderite. In this latter case we assume epitaxial relations.     

Thermal, micro-structural, and electrical properties of a La1−x Sr x Mn0.85Fe0.05Co0.05Ni0.05O3+δ (x = 0–0.4 mole) cathode system

The oxygen stoichiometry, thermal expansion, morphology, and electrical conductivity of a co-doped perovskitetype cathode system, La_1?x Sr _x Mn_0.85Fe_0.05Co_0.05Ni_0.05O_3+ä (x = 0–0.4 mole), are studied for intermediate-temperature solid oxide fuel cell applications. Sr²⁺-doping led to a decrease in the unit cell volume, oxygen stoichiometry, particle size, and activation energy, and an increase in the coefficient of thermal expansion and electrical conductivity. The sample with x = 0.3 mole exhibited four to five fold weight loss with respect to La_0.75Sr_0.25MnO_3+δ at an intermediate temperature range and suggested the availability of a large number of oxygen vacancies due to a co-doping effect. This sample also showed sufficiently high electrical conductivity (～76 S cm^?1) at 650 °C, a low activation energy (～0.15 eV), and a coefficient of thermal expansion (～12.1 × 10^?6 °C^?1) comparable to those of the adjacent components and submicron sized particles. The experimental results are explained using defect models.