Synthesis and electrochemical,electrical and gas sensing properties of novel mononuclear metal-free,Zn(II), Ni(II), Co(II), Cu(II), Lu(III) and double-decker Lu(III) phthalocyanines substituted with 2-(2H-1,2,3-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl) phenoxy

A new mono substituted phthalonitrile derivative 3 was prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with 2-(2H-1,2,3-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol. Novel metallophthalocyanines 4–8 (M = Zn, Ni, Co, Cu, Lu, respectively), metal free 9 and double decker Lu(III) phthalocyanine 10 with four peripheral 2-(2H-1,2,3-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenoxy groups were synthesized by cyclotetramerisation of the phthalonitrile and characterized by elemental analyses, FTIR, ¹H NMR, UV–vis and MALDI-TOF MS spectral data. Cyclic voltammetry, differential pulse voltammetry and in situ spectroelectrochemistry of the phthalocyanine compounds have been studied. This allowed us to identify and compare metal- and phthalocyanine ring-based redox processes of the complexes. Impedance spectroscopy (IS) and dc conductivity measurements were performed as a function of temperature (300–430 K) and frequency (40–10⁵ Hz.). The sensing properties of the films for toluene were also investigated. The dc results showed an activated conductivity dependence on temperature for all films. While room temperature impedance spectra consist of a curved line, a transformation into a full semicircle with increasing temperature was observed. The analysis of ac conductivity data showed that the CBH model is the dominant conduction mechanism for the electron transport in the films. While exposure to toluene has no effect on the conductivity of the film of 8–10 completely reversible sensor response to toluene only were obtained for compounds 4–7. It was also observed that the operating temperature had a considerable effect on sensing characteristics of the films.     

Synthesis,characterization, and electrical,electrochemical and gas sensing properties of a novel cyclic borazine derivative containing three phthalocyaninato zinc(II) macrocycles

A novel borazine derivative of trinuclear phthalocyanine has been prepared by following the multistep reactions of unsymmetrically substituted phthalocyanines. 4-(4-Amino-3-nitrophenoxy)phthalonitrile (3) which is one of the precursor molecules of the phthalocyanine was obtained from 4-nitrophthalonitrile (1) and 4-amino-3-nitrophenol (2) with K₂CO₃ in DMF at 50 °C. The zinc(II) phthalocyanine (5) containing an unsymmetrical substituted 4-amino-3-nitrophenoxy group was synthesized by statistical condensation of two different phthalonitriles. 4-(4-Amino-3-nitrophenoxy)phthalonitrile (3) and 4,5-bis(hexylthio)phthalonitrile (4) were cyclotetramerized with zinc acetate in DMF at 170–180 °C to yield 2-(4-amino-3-nitrophenoxy)-9,10,16,17,23,24-hexa(hexylthio)phthalocyanine zinc(II) complex (5), which was then separated by column chromatography on silica gel. The unsymmetrically substituted compound was reduced to the diamine form (6) using hydrazine hydrate in the presence of Pd/C catalyst, and the product was purified with chromatographic separation. Compound 6 was then reacted with triisopropoxyborane in refluxing xylene to give 5H,12H,19H-tris[2-(3,4-diaminophenoxy)-9,10,16,17,23,24-hexa(hexylthio)phthalocyaninato zinc(II) diazaborolo] borazine (7). The resulting product was purified by column chromatography on silica gel. All the target unsymmetrical phthalocyanines and borazine derivative were characterized by elemental analysis, IR, UV–vis, and ¹H NMR. Boron and zinc(II) percents in 7 were quantified with ICP-MS. Impedance spectroscopy and dc measurements were performed on spin coated 5–7 films as a function of temperature (293–400 K). The dc results showed an activated conductivity dependence on temperature. The ac results gave a temperature dependent frequency exponent s. The results were compared with the prediction of the Quantum Mechanical Tunelling and Correlated Barrier Hopping models. The ac conductivity of the films was well represented by the form Aω^s. Gas sensing properties of the films for the volatile organic compounds (VOCs) (chloroform, acetone, carbontetrachloride and ammonia) were also investigated in the temperature range from 293 to 400 K. The operating temperature had a considerable effect on sensing characteristics. Maximum sensitivity to VOCs were observed at room temperature for all films. Cyclic voltammetry of compounds 6 and 7 in solution indicated that these compounds have similar voltammetric behaviour.     

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.     

Synthesis,characterization, mesomorphic and electrical properties of tetrakis(alkylthio)-substituted lutetium(III) bisphthalocyanines

The synthesis of new lutetium(III) bisphthalocyanines substituted with alkylthio groups (1–5) is described. These compounds (Pc₂Lu) are soluble in most common organic solvents and have been fully characterized (elemental analysis, FT-IR, UV–Vis spectroscopy, mass spectrometry). The thermal stabilities of the Pc compounds were determined by thermogravimetric analysis (TGA). The mesogenic properties of these new materials forming columnar-hexagonal (Col_h) mesophases were studied by differential scanning calorimetry (DSC), optical microscopy and X-ray diffraction. The compounds 2–5 exhibit a double clearing point. DC electrical properties of these compounds in different phases were determined by measuring I–V characteristics and dark current of their thin films on interdigital electrodes. The measurements were carried out in ambient air, in vacuum and in high purity nitrogen (N₂) flow in the temperature range between 300 and 420 K. Dark current measurements obtained in the crystal, liquid crystal (LC) and isotropic liquid phases were in agreement with the phase transitions of these compounds obtained by DSC and optical microscopy results. The relation between the phase transition and conductivity of the Pc₂Lu derivatives were investigated. Also, the influence of the nature of the substituted group (alkylthia and alkoxy) upon the DC electrical properties of the Pc₂Lu derivatives was investigated. The DC conductivities and the thermal activation energies depending on alkyl chain lengths of these compounds were found to be in the range of 10^?8 to 10^?5 S/cm and 0.12–0.38 eV in solid phase.     

Synthesis,characterization and electrical and CO2 sensing properties of triazine containing three dendritic phthalocyanine

The metal-free phthalocyanine 1a was synthesised by statistically mixed condensation of 4-nitrophthalonitrile and 4-(2-dimethylaminoethylsulfanyl)phthalonitrile in dry 2-(dimethylamino)ethanol. The same route were applied to prepare metal-containing phthalocyanines using metal salts Zn(OAc)₃·2H₂O and CoCl₂, respectively, in dry DMF. The nitro compounds were reduced to amine with sodium sulfide and quarternized by reaction of MeI. These compounds were then reacted with cyanuric chloride in the presence of potassium carbonate as a base in mixture of THF and DMF gave s-triazine containing three amino phthalocyanines 4a–c. The reaction of three phthalocyanines with sodium salt of triethylmethanetricarboxylate in absolute ethanol were synthesised first generation of dendrimer 5a–c. The second generation of dendritic phthalocyanines 6a–c were prepared by the reaction of dentritic phthalocyanines with tris (H₂NC(CH₂OH)₃) using K₂CO₃ as a base in DMSO. The dendritic phthalocyanines containing tris are slightly soluble in water. The new compounds were characterized by elemental analysis and UV–vis, IR, NMR spectra. The temperature dependence of the dc and ac conductivity of these compounds and the adsorption of CO₂ gas on thin film of the compounds were investigated by dc conductivity and impedance spectroscopy technique using an interdigital transducer structure on glass substrate. While exposure to CO₂ have no influence on the electrical conductivity (ac and dc) of compound 6a and 6c, the conductivity of the film of 6b strongly depend on the presence of the CO₂ gas. Completely reversible sensor signals were obtained for compound 6b. The impedance spectra were obtained at frequencies between 40 and 10⁵ Hz, and in a wide range of CO₂ concentrations (from 500 to 8000 ppm) at room temperature. The temperature dependence of dc conductivity show typical Arrehenius behaviour for all compounds. The ac conductivity of the films is represented by the form ω^s. The dependency of frequency exponent s on temperature suggests a correlated barrier hopping (CBH).     

Novel cycloaurated gold(III) complexes and their effects on styrene polymerization

Novel cycloaurated gold(III) complexes were prepared by using Schiff bases with different substituents. Effects of the synthesized gold(III) complexes and substituent groups on styrene polymerization were investigated. As a result of these investigations, it was observed that gold(III) complexes could not catalyze polymerization reaction without addition of a co-catalyst like NaBAr′₄ (Ar′ = 3,5-bis(trifluoromethyl)phenyl). All ligands and complexes were characterized by using ¹H nuclear magnetic resonance (NMR), ¹³C-NMR, LC-MS, elemental analysis and FT-IR techniques. The architecture of the polymer was determined as an atactic or sydiotactic polymer by using ¹³C-NMR and DSC techniques. Molecular weights of the polymers were analyzed by using gel permeation chromatogram (GPC).     

The role of solvent on the doping of polyaniline with Fe(III) ions

The products formed from the reaction of emeraldine base polyaniline (EB-PANI) with Fe(III) ions in N-methyl-pyrrolidone (NMP), dimethylacetamide (DMA), dimethylformamide (DMF) and m-cresol media have been investigated using UV–VIS–NIR and resonance Raman (λ₀ = 632.8 and 1064 nm) spectroscopies. Through these results it was verified that the different PANI forms in solution can be formed by the suitable choice of the solvent. The behavior of Fe(III)/EB-PANI in different solvents was rationalized in terms of the interactions among Fe(III) ions, EB-PANI and solvent. In basic NMP, DMA and DMF media, the reaction of Fe(III) with EB-PANI yields EB-PANI doping giving ES-PANI and/or the EB-PANI oxidation to PB-PANI. The formation of ES-PANI is favored in DMF while PB-PANI is formed in a greater extension in NMP and DMA. In acidic m-cresol, only ES-PANI is produced in Fe(III)/EB-PANI solutions indicating the important role played by the solvent in the nature of the product.     

Group 11 complexes with the 1,1′Bis[N,N′-(2-(diphenylphosphino) amide] ferrocene ligand

The ligand 1,1-bis[N,N′-(2-diphenylphosphino) amide]ferrocene, Fc(CONHCH₂CH₂PPh₂)₂ (L), has been synthesized by reaction of the chloro carbonyl derivative Fc(COCl)₂ and the aminophosphine NH₂CH₂CH₂PPh₂. The coordination properties towards silver(I), gold(I) and gold(III) compounds have been explored. Several complexes with the diphosphine acting as bidentate chelating or bridgind ligand have been prepared. Furthermore the dinuclear species [Au₂Fc(CONCH₂CH₂PPh₂)₂] with the ligand coordinated through the phosphorus and the deprotonated amido group have been achieved.     

Supramolecular associates of double-decker lanthanide phthalocyanines with macromolecular structures and nanoparticles as the basis of biosensor devices

The electronic-spectroscopy technique is used to study the properties of solutions of double-decker diphthalocyanine complexes of lanthanides LnPc₂ (Ln = Ho, Er, Yb, Lu) in chloroform, dimethylformamide, water-micellar systems, solutions of proteins, and polymers, as well as on the surface of silica nanoparticles. In all the studied systems, a correlation is established between the positions of maxima of absorption bands of LnPc₂ and the ionic radius of the complexing metal. Redox processes determined by the nature of the solubilizer are detected in supramolecular associates of LnPc₂ with macrocompounds and nanoparticles. Finally, prototypes of sensor systems are suggested for determination of albumin and silica nanoparticles in solutions. Films of polyvinyl pyrrolidone and polyvinyl alcohol containing LuPc₂ and YbPc₂ are obtained, for which sensor response to albumin and nanosilica is also established. On the whole, the results show good prospects for development of sensor devices based on the studied systems.     

Conjugated complexes via oxidative complexation of polyaniline derivatives to vanadium(III)

The emeraldine base of poly(o-toluidine) and N,N′-bis(4′-dimethylaminophenyl)-1,4-quinonediimine were demonstrated to undergo oxidative complexation to VCl₃, affording the corresponding conjugated complexes. The complexation proceeds via reduction of the quinonediimine moiety with oxidation of V(III)–V(IV), in which the vanadium species is considered to play an important role in both the complexation and reduction.     

Coprecipitation thermodynamics of iron(II-III) hydroxysulphate green rust from Fe(II) and Fe(III) salts

Iron(II-III) hydroxysulphate GR(SO₄²⁻) was prepared by precipitating a mixture of Fe(II) and Fe(III) sulphate solutions with NaOH, accompanied in most cases by iron(II) hydroxide, spinel iron oxide(s) or goethite. Its [Fe(II)]/[Fe(III)] ratio determined by transmission Mössbauer spectroscopy was 2±0.2, whatever the initial [Fe(II)]/[Fe(III)] ratio in solution. Proportion of Fe(OH)₂ increased when the initial [Fe(II)]/[Fe(III)] ratio increased, whereas proportion of α-FeOOH or spinel oxide(s) increased when this ratio decreased. GR(SO₄²⁻) is metastable vs. Fe₃O₄ except in a limited domain around neutral pH. Precipitation from solutions containing both Fe(II) and Fe(III) dissolved species seems to favour GRs formation with respect to stable systems involving iron (oxyhydr)oxides.     

Extraction Separation of Sc(III) and Fe(III) from a Strongly Acidic and Highly Concentrated Ferric Solution by D2EHPA/TBP

The solvent extraction and separation process of Sc(III) and Fe(III) from a strongly acidic and highly concentrated ferric solution using mixtures of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) in sulfonated kerosene was studied. The effects of various parameters, including D2EHPA concentration, dosage of TBP, and phase ratio, were investigated for the extraction process. The results indicated that the extraction rate of Sc(III) was 99.72% with 1.09% Fe(III) co-extracted after two stages of counter-current extraction under optimal conditions. Moreover, saturation capacity and slope analysis were used to determine the reaction mechanism. Sc(III) is extracted in the form of HSc(SO₄)₂·4HL. Further separation of Sc(III) and Fe(III) was realized in a scrubbing and stripping process. First, 98.67% of the co-extracted iron in the loaded organic phase was scrubbed with a dilute HCl solution by a three-stage counter-current scrubbing. Then, 85.00% of Sc(III) can be stripped efficiently with a 2-mol/L NaOH solution saturated in 1-mol/L NaCl by three-stage cross-current stripping.     

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.     

Self-healing mechanism of an organosiloxane polymer film containing sodium silicate and cerium(III) nitrate for corrosion of scratched zinc surface in 0.5 M NaCl

A highly protective and self-healing film of 1,2-bis(triethoxysilyl)ethane (C₂H₅O)₃Si(CH₂)₂Si(OC₂H₅)₃ polymer containing sodium silicate (water glass) Na₂Si₂O₅ and cerium(III) nitrate Ce(NO₃)₃ was prepared on a zinc electrode previously treated in a Ce(NO₃)₃ solution. The film was examined by polarization measurement of the electrode in an aerated 0.5 M NaCl solution after the electrode was scratched and immersed in the solution for 4-72 h. Self-healing mechanism of the film was investigated by X-ray photoelectron spectroscopy and electron-probe microanalysis for the coated electrode surface after scratched and immersed in the NaCl solution. A passive film composed of Zn(OH)₂, ZnSi₂O₅ and Ce³⁺-Si₂O₅²⁻ salt or complex was formed on the scratched surface and preferential deposition of Si₂O₅²⁻ compounds occurred at a defect of the passive film where Cl⁻ accumulated, resulting in suppression of pitting corrosion at the scratch.     

Crystal structure of R3Ge4 compounds (R Er, Ho, Tm, Lu)

The crystal structure of binary germanides R₃Ge₄ (R Er, Ho, Tm, Lu) has been determined by means of powder X-ray diffraction. For Er₃Ge₄ a full-structure determination has been performed using the Rietveld method (306 reflections, space group Cmcm,

Full-size image (2K)

). The location of the atoms in Er₃Ge₄ is similar to that in the W₃CoB₃ structure, with the Ge atoms substituting for Co and B. For the other R₃Ge₄ compounds (RHo, Tm and Lu) the lattice parameters are given.     

Synthesis,photoluminescent and electroluminescent properties of a novel europium(III) complex involving both hole- and electron-transporting functional groups

A novel europium(III) complex involving a carbazole fragment as hole-transporting group and an oxadiazole fragment as electron-transporting group was synthesized and used as red light-emitting material in organic light-emitting diodes (OLEDs). The complex is amorphous, and exhibits high glass transition temperature (T_g = 157 °C) and high thermal stability with a 5% weight loss temperature of 367 °C. Two devices, device 1: ITO/NPB (40 nm)/Eu(III) complex (30 nm)/Alq₃ (30 nm)/LiF (1 nm)/Al (100 nm) and device 2: ITO/NPB (40 nm)/3% Eu(III) complex: CBP (30 nm)/BCP (10 nm)/Alq₃ (30 nm)/LiF (1 nm)/Al (100 nm), were fabricated, where NPB is N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine, Alq₃ is tris(8-hydroxyquinoline) Al(III), CBP is 4,4′-bis(carbazole-9-yl)-biphenyl, and BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, respectively. In contrast with device 1, owing to less self-quenching and better charge confinement, device 2 shows improved performances: the maximum luminance of device 2 was dramatically increased from 199 to 1845 cd/m², the maximum current efficiency was increased from 0.69 to 2.62 cd/A, the turn-on voltage was decreased from 9.5 to 5.5 V, and higher color purity was attained.     

Metal ion sensing functional mono and double-decker lanthanide phthalocyanines: Synthesis,characterization and electrical properties

We report, in this study, the preparation, physical characterization metal ion sensing properties of peripherally functionalized ionophore ligand, 4,5-bis(6-hydroxyhexylthio)-1,2-dicyanobenzene (1) and its mono 2,3,7,8,12,13,17,18-octakis(6-hydroxyhexylthio)phthalocyaninatometal (II) {M = Zn^II (2), Cu^II (3)} and double-decker lanthanide bis-phthalocyanines, {([4,5,4′,5′ 4″,5″,4?,5?]-tetrakis-(6-hydroxyhexylthio)phthalocyaninatolanthanium(III)}){M[Pc(S–C₆H₁₃OH)₄]₂} {M = Eu^III (4), Yb^III (5), and Lu^III (6)}. All benzenes on phthalocyanines are functionalized with hydroxyhexylsulfanyl moieties for potential use as soft metal ion binding, such as Ag⁺ and Pd²⁺. The temperature dependence of the dc and ac conduction properties of 4, 5 and 6 thin films have been investigated in the frequency range of 40–10⁵ Hz and temperature range 290–436 K. The dc results showed an activated conductivity dependence on temperature for all films. Obtained data reveal that ac conductivity obeys the relation σ_ac(ω) = Aω^s and exponent is found to decrease by increasing temperature. The data obtained results were compared with the prediction of the Quantum Mechanical Tunelling (QMT) and Correlated Barrier Hopping (CBH) models. The analysis showed that the CBH model is the dominant conduction mechanism for the electron transport in the films. The new synthesized compounds have been characterized by elemental analysis, FTIR, ¹H and ¹³C NMR, MS, UV–vis and EPR spectral data.     

Synthesis and properties of μ-cyano(phthalocyaninato)-rhodium(III)

This contribution reports on the synthesis of μ-cyano(phthalocyaninato)rhodium(III), [PcRhCN]_n (1), by splitting off potassium cyanide from potassium(dicyano)phthalocyaninatorhodium(III), K[PcRh(CN)₂] (2). Monomeric complexes, PcRh(L)CN (7), were formed when [PcRhCN]_n (1) was treated with base molecules L, such as n-butylamine and pyridine. All compounds were characterized by IR, far-IR spectroscopy, thermal and elemental analyses, and partly by UV, ¹H-NMR and FD (field desorption) mass spectroscopy. The undoped polymer [PcRhCN]_n (1) exhibits a d.c. dark conductivity of 4 × 10^?4 S/cm, which was diminished by eight orders of magnitude when the polymeric structure was decomposed by treatment with a competing ligand.     

Synthesis,characterization and electrical properties of novel metal-free,Co(II), Cu(II), Fe(II), Mn(II), Sn(II) phthalocyanines peripherally tetra-substituted with 2,3-dihydro-1H-inden-5-yloxy moiety

Novel metal-free and metal (Co, Cu, Fe, Mn and Sn) phthalocyanines were synthesized by cyclotetramerization of 4-(2,3-dihydro-1H-inden-5-yloxy)phthalonitrile and characterized by elemental analyses, IR, UV–vis and MALDI-TOF mass spectral data. The effect of metals on spectroscopic properties and aggregation behaviours of the novel Pcs were investigated in different concentration and solvents. Their electrical transport and dielectric properties were also investigated. The ac conductivity showed strong dependence on both temperature and frequency. The temperature dependence of frequency exponent s suggested a dominant hopping conduction process. It was observed that tan δ increases as the frequency increases and reaches a maximum and thereafter decreases. As the temperature increases the frequency at which tan δ reaches a maximum shifted towards higher frequencies.     

A binuclear aluminum(III) complex: Thermal stability,photophysical, electrochemical and electroluminescent properties

A novel binuclear aluminum(III) complex with acylpyrazolone derivative as ligands, bis(salicylidene-o-aminophenol)-bis(4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one)-bis-aluminum(III) [Al₂(saph)₂(PMBP)₂] was designed and synthesized. A detailed study was carried out on its thermal stability, photophysical, electrochemical and electroluminescent properties. It was found that the introduction of 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (PMBP) ligands improved the thermal stability remarkably. Organic light-emitting diodes (OLEDs) based on this Al complex as the sole emitter and the host for red dopant were fabricated. Bright green-yellow emission was observed from the device using Al₂(saph)₂(PMBP)₂ as the emitter and the electron transporting layer. Pure red emission peaked at 632 nm was obtained from the Al₂(saph)₂(PMBP)₂ doped with DCJTB [4-(dicyanomethylene)-2-tertbutyl-6(1,1,7,7,-tetramethyljulolidyl-9-enyl)-4H-pyran] device with a luminance efficiency of 1.51 cd/A at 200 A/m². No light from Al₂(saph)₂(PMBP)₂ was found, indicating that the matched energy levels provide an efficient red emission system in Al₂(saph)₂(PMBP)₂ device. Those results demonstrated that Al₂(saph)₂(PMBP)₂ might be a promising material for OLEDs.