Metal Complex Compounds Research Articles

Synthesis and characterization of novel polyphenol species derived from bis(4‐aminophenyl)ether: Substituent effects on thermal behavior, electrical conductivity, solubility, and optical band gap

AbstractIn this study, four different Schiff bases namely 4,4′‐oxybis[N‐(2‐hydroxybenzilidene)aniline] (2‐HBA), 4,4′‐oxybis[N‐(4‐hydroxybenzilidene)aniline] (4‐HBA), 4,4′‐oxybis[N‐(3,4‐dihydroxybenzilidene)aniline] (3,4‐HBA), and 4,4′‐oxybis[N‐(4‐hydroxy‐3‐methoxybenzilidene)aniline] (HMBA) were synthesized. These Schiff bases were converted to their polymers that have generate names of poly‐4,4′‐oxybis[N‐(2‐hydroxybenzilidene)aniline] (P‐2‐HBA), poly‐4,4′‐oxybis[N‐(4‐hydroxybenzilidene)aniline] (P‐4‐HBA), poly‐4,4′‐oxybis[N‐(3,4‐dihydroxybenzilidene)aniline] (P‐3,4‐HBA), and poly‐4,4′‐oxybis[N‐(4‐hydroxy‐3‐methoxybenzilidene)aniline] (PHMBA) via oxidative polycondensation reaction by using NaOCl as the oxidant. Four different metal complexes were also synthesized from 2‐HBA and P‐2‐HBA. The structures of the compounds were confirmed by FTIR, UV‐vis, 1H and 13C NMR analyses. According to 1H NMR spectra, the polymerization of the 2‐HBA and 4‐HBA largely maintained with COC coupling, whereas the polymerization of the 3,4‐HBA and HMBA largely maintained with CC coupling. The characterization was made by TG‐DTA, size exclusion chromatography and solubility tests. Also, electrical conductivity of the polymers and the metal complex compounds were measured, showing that the synthesized polymers are semiconductors and their conductivities can be increased highly via doping with iodine ions (except PHMBA). According to UV–vis measurements, the optical band gaps (Eg) were found to be 3.15, 2.06, 3.23, 3.02, 2.61, 2.47, 2.64, 2.42, 2.83, 2.77, 2.78, and 2.78 for 2‐HBA, P‐2‐HBA, 4‐HBA, P‐4‐HBA, 3,4‐HBA, P‐3,4‐HBA, HMBA, PHMBA, 2‐HBA‐Cu, 2‐HBA‐Co, P‐2‐HBA‐Cu, and P‐2‐HBA‐Co, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Work function and valence band structure of tin-doped indium oxide thin films for OLEDs

Transparent conducting ITO thin film has been widely used as anode material in OLEDs due to its good optical transparency, low electrical resistivity, ease of patterning, high work function and efficient hole injection properties. The interface between ITO and organic layer in OLED device is thus important and can influence the electrical and luminescent properties. In this report, ITO substrates were treated with 20% H 3PO 4 solution. The corresponding changes in crystalline morphology were studied by X-ray diffraction. X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) were performed at ∼10 −9 Torr to study the work function and the valence band structure of ITO substrates. It was found that work function became slightly lower after the treatment, probably caused by the formation of metal complex compounds and metal hydroxides. The binding energy of In 3d 5/2 shifted from 444.6 to 445.3 eV. This shifting was referred to the formation of In–OH bonding. It would be easier to provide electron by In–OH bonding than by In–O–In or Sn–O–Sn when photons reached ITO surface. The interface between ITO and CuPc was improved through polar surface and less aggregation. In addition, the OLED devices exhibited improved performance in both external quantum efficiency and luminescence efficiency.

Structure of trans-diaqua-bis(3-hydroxybenzoylhydrazine)copper(II) sulfate monohydrate, [Cu(C7H8O2N2)2(OH2)2]SO4·H2O

Synthesis, X-ray phase analysis (XRPA), and IR spectroscopic study were performed to investigate the structure of [Cu(m-HBH)2(OH2)2]SO4·H2O, where m-HBH = C7H8O2N2 (3-hydroxybenzoylhydrazine); a = 7.154(3) A, b = 8.012(2) A, c = 20.061(2) A, β = 90.56(2)°; P21, Z = 2, R(F) = 0.046. The structure of the compound consists of the [Cu(m-HBH)2(OH2)2]2+ complex cations, SO42− anions, and one water molecule. The copper atom is surrounded by a tetragonal bipyramid; c.n. is 6 = 4 + 2 (the distances are 2.030(5) A, 2.054(6) A, 2.061(5) A, and 2.097(3) A (equatorial); 2.459(4) A and 2.53(4) A (axial)). In complex compounds of 3d metals containing m-HBH, the function of the latter is probably invariable; the distribution of the anions and water molecules in the structure depends on the type of the metal and on the anion shape and geometry for metals with slightly different ionic radii.

Studies in the field of electrochemistry of organic compounds in 2000–2006

This review presents the author’s views on the state-of-art in the electrochemistry of organic compounds, based on the analysis of the data published from 2000 to 2006. The number of publications that consider to one or another extent the electrochemical reactions involving organic compounds constantly increases. The range of problems studied is intimately related with the demands of new technologies. The largest number of publications are devoted to the electrochemical polymerization and the properties of polymeric films on the electrode surface and also to the mechanism of electrode reactions of metal-complex compounds and their properties. The directions such as electrochemistry of nanomaterials and the methods of modification of electrodes are largely associated with the use of electroactive polymers. Fine organic electrosynthesis including the technological developments in the destruction of organic compounds, e. g., for cleaning of waste water, fade to the background. A new direction in this field is the development of amperometric sensors that employ modified electrodes based on electrochemically activated polymeric films.

Synthesis, characterization, conductivity, band gap and thermal analysis of poly-2-[(4-mercaptophenyl) imino methyl] phenol and some of its polymer–metal complexes

The oxidative polycondensation reaction conditions of 2-[(4-mercaptophenyl) imino methyl] phenol (4-MPIMP) was studied in an aqueous alkaline medium between 30 and 90 °C by using oxidants such as air O 2, NaOCl and H 2O 2. Polymer–metal complex compounds were synthesized from the reactions of poly-2-[(4-mercaptophenyl) imino methyl] phenol (P-4-MPIMP) with Cr 3+, Co 2+, Ni 2+, Cu 2+, Mn 2+, Zn 2+, Pb 2+, Cd 2+ and Zr 4+ ions. The structures of these monomer and polymer were identified from UV–vis, FT-IR, 1H NMR, 13C NMR and elemental analysis. While thermal analysis of P-4-MPIMP and polymer–metal complexes were made by TGA–DTA, the number-average molecular weight ( M n), weight-average molecular weight ( M w) and polydispersity index (PDI) values of this polymer were determined by size exclusion chromatography (SEC). According to TG–DTA analyses, P-4-MPIMP–Cu was found to be higher stable than other synthesized polymer and polymer–metal complexes. While conductivity measurements of polymer and polymer–metal complexes were done by electrometer using four point probe techniques, electrochemical and optical band gap values of 4-MPIMP, P-4-MPIMP and polymer–metal complexes were determined by using cyclic voltammetry and UV–vis measurements. Conductivity and band gap values show that this polymer and polymer–metal complexes are a typical semiconductor.

Synthesis, Characterization and Thermal Degradation Oligomer and Monomer/Oligomer Metal Complex Compounds of 2‐Methylquinolin‐8‐ol

The oxidative polycondensation of 2‐methylquinolin‐8‐ol (2‐MQ) has been accomplished by using H2O2 oxidant in aqueous alkaline medium. Optimum reaction conditions of the oxidative polycondensation and the main parameters of the process were established. At optimum reaction conditions, yield of the products was found to be 32.0%. The structures of the obtained monomer and oligomer were confirmed by FT‐IR, UV‐vis, 1H‐NMR, 13C‐NMR and elemental analysis. The characterization was made by TG‐DTA, using size exclusion chromatography (SEC) and solubility tests. The FT‐IR, 1H‐NMR and 13C‐NMR data shows that the polymerization proceeded by the C‐C coupling of ortho and para positions according to ‐OH group of 2‐MQ. The molecular weight distribution values of the product were determined by SEC. The number‐average molecular weight (Mn), weight‐average molecular weight (Mw) and polydispersity index (PDI) values of O‐2‐MQ were found to be 1980, 3312 and 1.681 for H2O2 oxidants, respectively. Thermal analysis results of O‐2‐MQ demonstrated to be stability against thermal decomposition. Thermal analyses of 2‐MQ‐Cd, 2‐MQ‐Co, 2‐MQ‐Cu, 2‐MQ‐Zn, O‐2‐MQ‐Cd, O‐2‐MQ‐Co, O‐2‐MQ‐Cu, and O‐2‐MQ‐Zn monomer/oligomer‐metal complex compounds were investigated in a N2 atmosphere between 15–1000°C.

Studies on thermal degradation of oligo-2-[(4-morpholin-4-yl-phenyl)imino methyl] phenol and oligomer–metal complex compounds

Thermogravimetric studies of 2-[(4-morpholin-4-yl-phenyl) imino methyl]phenol (2-MPIMP), oligo-2-[(4-morpholin-4-yl-phenyl) imino methyl] phenol (O-2-MPIMP) and its oligomer–metal complex compounds were investigated by thermal analysis. Four kinetic methods were used to investigate the thermal decomposition of these materials. These investigated methods are those of Coats and Redfern (CR), MacCallum and Tanner (MC), van Krevelen (vK) and Madhusudanan, Krishnan and Ninan (MKN). The values of the apparent activation energies of thermal decomposition E a, the reaction order n, pre-exponential factor A, the entropy change ΔS *, enthalpy change ΔH *, free energy change ΔG *, obtained by the above-mentioned methods were all in good in agreement with each other. It was found that the thermal stabilities of the complexes follow the order Cu(II) > Co(II) > Zn(II) > Zr(IV) > Pb(II) > Cd(II).

About the role of hybridization in wetting and friction on Al-based complex metallic compounds

The reversible adhesion energy of water was deduced for many Al-base conventional and complex intermetallics from contact angle measurements performed at the surface of the native oxide layer that always exists in air on top of such materials. Surprisingly, this quantity shows a direct correlation with the density of states at the Fermi level in the bulk material. Similarly, we obtained a straightforward assessment of the surface energy of Al-base complex intermetallics using pin-on-disk measurements performed in a vacuum chamber (using an adequate calibration procedure). For the two types of data, we stress in this article the important role played by the hybridization that occurs between Al p–d and transition metal (TM) d states in the bulk specimen, a mechanism that is also responsible for the specific stability of quasicrystals and high-rank approximants in Al- (TM) systems.

Synthesis, characterization, conductivity and thermal degradation of oligo-2-[(4-morpholin-4-yl-phenyl)imino]methylphenol and its oligomer–metal complex compounds

Schiff base oligomer of 2-[(4-morpholin-4-yl-phenyl)imino]methylphenol (2-MPIMP) was synthesized via oxidative polycondensation reaction by using air O 2 and NaOCl oxidants in an alkaline medium between 40 and 90 °C. The structure of oligo-2-[(4-morpholin-4-yl-phenyl)imino]methylphenol (O-2-MPIMP) was characterized by using 1H, 13C NMR, FT-IR, UV–vis, size exclusion chromatography (SEC) and elemental analysis techniques. At the optimum reaction conditions, the yield of O-2-MPIMP was found to be 73% (for air O 2 oxidant) and 97% (for NaOCl oxidant). According to the SEC measurements, the number-average molecular weight ( M n), weight-average molecular weight ( M w) and polydispersity index (PDI) values of O-2-MPIMP was found to be 1725, 2030 mol −1 and 1.177, respectively, using air O 2 and 1345, 1490 g mol −1 and 1.108, using NaOCl, respectively. Oligomer–metal complex compounds were synthesized from the reactions of O-2-MPIMP with Cu 2+, Co 2+, Cd 2+, Zn 2+, Pb 2+ and Zr 4+ ions. Electrochemical the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical energy gaps ( E ′ g ) for 2-MPIMP and O-2-MPIMP were found to be between −5.85 and −5.82, −2.63 and −2.87, 3.22 and 2.95 eV. Also, conductivity values of oligomer and oligomer–metal complex compounds were determined from their solid conductivity measurements. Conductivity measurements of doped and undoped Schiff base oligomer and its metal complexes were carried out by electrometer at room temperature and atmospheric pressure and were calculated from four-point probe technique. When iodine was used as doping agent, conductivity of this oligomer and its metal complexes were observed to be increased.

Conductivity and band gap of oligo-2-[(4-chlorophenyl) imino methylene] phenol and its oligomer–metal complexes

Schiff base oligomer of 2-[(4-chlorophenyl) imino methylene] phenol (CPIMP) was synthesized via oxidative polycondensation reaction in an alkaline medium. Oligomer–metal complex compounds were synthesized from the reactions of oligo-2-[(4-chlorophenyl) imino methylene] phenol (OCPIMP) with Co+2, Ni+2 and Cu+2 ions. The synthesis was achieved by oxidative coupling based on air oxygen as an oxidant. While synthesized Schiff base oligomer was soluble in most common organic solvents, its metal complexes were only soluble in dimethylsulfoxide. Electrochemical HOMO and LUMO band gap (Eg) of this oligomer and its metal complexes were found to be between −6.17, −5.28 and −2.91, −3.26 and 3.29 and 2.02 eV, respectively. However optical band gap (Eg) of this oligomer and its metal complexes were calculated from their absorption edges and were found between 2.26 and 3.18 eV. Conductivity measurements of doped and undoped Schiff base oligomer and its metal complexes were carried out by electrometer at room temperature and atmospheric pressure and were calculated from four-point probe technique. When iodine was used as doping agent, conductivity of this oligomer and its metal complexes were observed to be increased.

Penning ionization electron spectroscopy of (η 6-C 6H 6)Cr(CO) 3 and (η 5-C 5H 5)Mn(CO) 3

Penning ionization electron spectra of half-sandwich metal complex compounds ((η 6-C 6H 6)Cr(CO) 3 and (η 5-C 5H 5)Mn(CO) 3) by collision with He *(2 3S) metastable atoms were observed. With collision-energy/electron-energy-resolved measurement of ejected electrons, information on anisotropic interaction potential energy for the spatial region where the corresponding MO extends were investigated by measuring collision energy dependence of partial ionization cross-sections (CEDPICS) for each ionic state. Assignments of ionic states are also discussed on basis of orbital reactivity of Penning ionization, slope of CEDPICS, and an orbital energy calculation by density functional theory. Since similarity between an excited He *(2 3S) atom and a ground state Li atom is known in interaction with targets, quantum chemical calculations for intramolecular interactions with a Li(2 2S) atom are also performed. Large reactivity and strong attractive interactions are observed around oxygen atoms of carbonyl groups. On the other hand, repulsive or weak attractive interactions are also found for the benzene and cyclopentadienyl rings.

Complexation as the most important factor in the fate and transport of heavy metals in the Dnieper water bodies.

The results of long-term investigations of the concentrations of dissolved forms of some heavy metals (Mn, Cu, Zn, Pb, Cr, Cd) and their species in the water of the Dnieper reservoirs and the Dnieper-Bug estuary are considered. Chemiluminescent methods, anodic stripping voltammetry, membrane filtration, ion-exchange, and gel-permeation chromatography were used for study of the speciation of the metals. It has been found that binding of heavy metals into complexes with dissolved organic matter (DOM) is the dominant factor of their stabilization in solution. The molecular weight distribution of organic metal complexes and their chemical nature, as well as the potential complexing ability of DOM were investigated. Humic substances, particularly fulvic acids, play a major role in the complexation. These ligands bind from 45 to 80% of metals in the form of organic complexes. Metal complex compounds of relatively low molecular weight (<5 kDa) predominated in the organic complexes.

Zinc, lead and cadmium speciation in Dnieper water‐bodies

AbstractData on the concentrations and movements of Zn, Pb and Cd in Dnieper reservoirs and the Dnieper‐Bug estuary are considered. There is a clear trend of increasing concentrations, often two‐ to fourfold, of these materials from the 1960s to the end of the 1980s. Large increases may be explained as the result of increased human impact on the water‐bodies and also because of reduced water discharge in the Dnieper River (discharge has been reduced by nearly 10 km3 in recent years). At present, the average concentrations of Zn, Pb and Cd in Dnieper water‐bodies are 35.0–50.0, 15.0–18.0 and 0.5–1.8 μg L–1, respectively. Anodic stripping voltammetry, membrane filtration, ion‐exchange and gel permeation chromatography on neutral sephadexes were methods used for analysis. The influence of adsorption and complexation processes on the mobility of Zn, Pb and Cd, and the ratio of their forms were compared. Ratios of free metal ions to ions bound in complexes with natural organic ligands were studied. The binding of metals in complexes with dissolved organic matter (DOM), or their adsorption onto suspended particles, were major processes reducing the concentration of free ions in their most toxic form. The percentage of Zn, Pb, and Cd free ions in the total balance of dissolved forms was no more than 3.6–4.8, 0.2–0.6 and 7.2–9.5%, respectively. The molecular‐weight distribution of organic metal complexes and their chemical nature, as well as the potential for complexing of DOM were investigated. Most Zn, Pb and Cd was found as complex compounds with DOM of different chemical natures and molecular weights. Humic substances, particularly fulvic acids, played a major role in the migration of the metals. These ligands bind from 40 to 80% of metals in the composition of organic complexes. Metal complex compounds of relatively low molecular weight (&lt; 5000 Da) predominated in organic complexes of Zn (38–50%), Pb (38–52%) and Cd (22–47%). The role of inorganic ligands in complexation in surface waters was less important.

Catalysts for sanitary air cleaning from ozone

The results of the kinetic study of ozone decomposition over carbon fibrous materials and metal complex compounds (CuCl 2) supported on them at ozone concentrations in the 3.1 × 10 –8–3.1 × 10 –5 mol/l range are presented. Ozone decomposition occurs mainly in a catalytic way with the steady-state regime attainment depending on CFM physico-chemical as well as structural characteristics and macrokinetic factors of the process. Copper (II) catalyzes decomposition of ozone microconcentrations only. The data obtained can be a base for the development of sanitary air cleaning units and respirators (protective gas-masks).

Nanocomposites Built from MoS2 and Various Metal-Containing Layers

Restacking of exfoliated MoS2 in the presence of cationic metal complexes (M ˭Fe, Co, Ni, Ru) or metallic cations (M ˭Mn, Fe Co, Ni) leads to nanocomposite materials consisting of alternating layers of molybdenum disulfide and metal complex compounds or metal hydroxide clusters respectively.

5625107 Catalyst for conversion of methane to ethylene, preparation thereof, and process for manufacturing ethylene using said catalyst

The present invention relates to a new catalyst for converting methane into ethane, preparation thereof, and process for manufacturing ethylene using said catalyst. The conversion reaction catalyst in the present invention is employed in converting directly methane or methane-containing gas in the presence of the above catalyst with the following general formula (1). Ma.Pc.D/S (1) Where, M is a metal cluster or metal complex compound selected from the group of VIII, VII and VI series; S is an inorganic carrier; P is a promoter of phosphorus compound; D is a cobalt compound. And "a" is weight percentage of metal cluster or metal complex compound in catalyst, having a value of 0.01 to 10, "c" is weight percentage of promoter in catalyst, ranging from 1.0 to 35.0.

Formation of mixed-metal binuclear carbonyl ions [MCr(CO)n]+ in the gas phase by the laser ablation-molecular beam method

In the laser ablation–molecular beam (LAMB) method, laser ablation of metal substrates in vacuum is utilized for the formation of novel organometallic and metal complex compounds containing monopositive metal ions. Mixed-metal binuclear carbonyl ions [MCr(CO)n]+, n=0–6, are prepared in the gas phase by the reaction of laser-ablated metal ions (M+) and Cr(CO)6 in the molecular beam injected nearby. The relative abundance of these ions, for M=transition metals, can essentially be explained by the M+–Cr bond dissociation energies. Results of density functional calculation show that this is essentially valid. © 1997 John Wiley & Sons, Ltd.

RGB luminescence from passive-matrix organic LED'S

We fabricated an 8/spl times/9 (3RGB) passive matrix of organic light-emitting diodes (OLED's) and operated it at a video-rate to simulate NTSC signals. The color purity of red emission was improved by controlling the depth distribution of DCM in the Alq/sub 3/ layer. A newly synthesized binuclear metal complex compound was incorporated for blue emission and provided good chromaticity. We found that the rectification property of the OLED is important to drive a passive matrix and about 10/sup 5/ OLED pixels can be driven when aluminum is used as the cathode material.

Effects of some chelating agents on the uptake and distribution of 54Mn(II) in the brown trout (Salmo trutta).

The effects of humic acids, which are natural metal-complexing compounds, and potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate, which are sulphur-containing man-made chelating agents, on the uptake and tissue distribution of 54Mn(II) were studied in brown trout (Salmo trutta). Fish were exposed for 7 days to 0.1 microgram Mn(II).l-1 as MnCl2 (1 microCi 54MN.l-1) with or without chelating agents. Examination of the partition of Mn between octanol and a Tris-HCl buffer in the presence of these compounds was also performed. Humic acids had only small effects on Mn uptake and distribution in trout, probably because of the low stability of Mn-humate complexes. Partition of Mn in the presence of potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate between octanol and Tris-HCl buffer showed formation of lipophilic complex with the latter two compounds, but not with the former. However, these four chelating agents all decreased Mn uptake in the trout by 40-45%. These substances also changed the distribution of Mn within the fish, with a higher proportion of the metal being present in some visceral organs and a smaller proportion being localized in some non-parenchymateous tissues, such as skins, fins and bones. The mechanisms underlying these effects are not known. However, the interaction of chelating agents with the Mn, although weak, may have partially withdrawn the metal from the uptake process in the gills. The redistribution of Mn in the fish may be due to the binding of the metal to complexing compounds which have reached the intestinal lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

ChemInform Abstract: Synthesis of Metal Sulfides from Metal Complex Compounds with Sulfur‐ Containing Organic Ligands as Anions

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.