7440-66-6Relevant articles and documents
Excitons and excitonic molecules in mixed Zn(P1-xAsx)2 crystals
Yeshchenko,Biliy,Yanchuk
, p. 231 - 238 (2001)
Low-temperature (1.8 K) excitonic absorption, reflection and photoluminescence spectra of mixed Zn(P1-xAsx)2 crystals have been studied at x = 0.01, 0.02, 0.03 and 0.05. Energy gap and rydbergs of excitonic B-, C- and A-series decrease monotonically with increasing of x. The spectral half-widths of the absorption n = 1 lines of the B- and A-series increase monotonically with increase in x due to fluctuations of crystal potential. Emission lines of excitonic molecules have been observed in photoluminescence spectra of Zn(P1-xAsx)2 crystals. The binding energy of the molecule increases with increase in x due to the decrease of the electron-hole mass ratio.
Investigation of Sn-Zn electrodeposition from acidic bath on EQCM
Arici, Mürsel,Nazir, Hasan,Aksu, M. Levent
, p. 1534 - 1537 (2011)
Tin-zinc (Sn-Zn) alloy with low tin content was deposited on gold electrode and steel substrate with use of chronoamperometric technique from an acidic bath. In order to evaluate coating efficiency of Sn-Zn alloy in 0.5 M NaCl solution, open circuit potential-time curve (EOCP-t), polarization curves, mass change of the electrode (Δm-t) using quartz crystal microbalance (QCM) were compared to those of pure Sn and Zn coatings. Anodic stripping measurements were carried out simultaneously with the mass loss of the deposit. Scanning electron microscopy (SEM) and energy dispersive X-ray spectra (EDS) analysis were performed to characterize the surface morphology. Anodic stripping experiment and EDS analysis indicated that Sn, Zn, and SnO2 formed on the electrode surface when Sn-Zn was coated from acidic bath. Furthermore, local mapping demonstrated homogeneous distribution of Sn and Zn atoms throughout the surface.
Electron-poor antimonides: Complex framework structures with narrow band gaps and low thermal conductivity
Haeussermann, Ulrich,Mikhaylushkin, Arkady S.
, p. 1036 - 1045 (2010)
Binary zinc and cadmium antimonides and their ternary relatives with indium display complex crystal structures, but reveal at the same time narrow band gaps in their electronic structure at or close to the Fermi level. It is argued that these systems represent electron-poor framework semiconductors (EPFS) with average valence electron concentrations between three and four. EPFS materials constituted of metal and semimetal atoms form a common, weakly polar framework containing multi-center bonded structural entities. The localized multi-center bonding feature is thought to be the key to structurally complex semiconductors. In this respect electron-poor antimonides become related to modifications of elemental boron. Electron-poor antimonides show promising thermoelectric properties, especially through a remarkably low thermal conductivity. At the same time the thermal stability of these compounds is rather limited because of temperature polymorphism and/or comparatively low melting or decomposition temperatures (usually below 600 K).
Activation of Reduction Agents. Sodium Hydride Containing Complex Reducing Agents. 18. Study of the Nature of Complex Reducing Agents Prepared from Nickel and Zinc Salts
Brunet, Jean-Jacques,Besozzi, Denis,Courtois, Alain,Caubere, Paul
, p. 7130 - 7135 (1982)
Complex reducing agents NaH-RONa-MXn (referred to as MCRA) are new versatile reagents that have already found many applications in organic synthesis.In the present study, the composition and structure of NiCRA and ZnCRA (CRA prepared from a nickel salt and a zinc salt, respectively) have been investigated.It has been found that, in both reagents, the metal (Ni or Zn) is formallly in a zero-valent oxidation state.The active part of NiCRA is constituted of new species (formed from Ni0 (1 equiv), RONa (R = t-Bu) (2 equiv), NaH (2 equiv), and maybe some AcONa) in which each constituent has lost its own characteristics.A picture of the structure of these new species is proposed.The composition of the active part of ZnCRA is less clear.Indeed, associations between RONa (R = t-Am) and Zn0 have been evidenced, but these species do not exhibit the reducing properties of ZnCRA, e.g., toward carbonyl compounds.In fact, control experiments have shown that no ketone reduction occured in the absence of NaH.These observations led us to propose that the active part of ZnCRA should be constituted of associations of the type n, which may be formed, in low concentration, from NaH and the inactive species n.
Unexpected visible light driven photocatalytic activity without cocatalysts and sacrificial reagents from a (GaN)1-: X(ZnO)x solid solution synthesized at high pressure over the entire composition range
Dharmagunawardhane, H. A. Naveen,James, Alwin,Wu, Qiyuan,Woerner, William R.,Palomino, Robert M.,Sinclair, Alexandra,Orlov, Alexander,Parise, John B.
, p. 8976 - 8982 (2018)
Optical and photocatalytic properties were determined for the solid solution series (GaN)1-x(ZnO)x synthesized at high pressure over the entire compositional range (x = 0.07 to 0.9). We report for the first time photocatalytic H2 evolution activity from water for (GaN)1-x(ZnO)x without cocatalysts, pH modifiers and sacrificial reagents. Syntheses were carried out by reacting GaN and ZnO in appropriate amounts at temperatures ranging from 1150 to 1200 °C, and at a pressure of 1 GPa. ZnGa2O4 was observed as a second phase, with the amount decreasing from 12.8 wt% at x = 0.07 to ~0.5 wt% at x = 0.9. The smallest band gap of 2.65 eV and the largest average photocatalytic H2 evolution rate of 2.31 μmol h-1 were observed at x = 0.51. Samples with x = 0.07, 0.24 and 0.76 have band gaps of 2.89 eV, 2.78 eV and 2.83 eV, and average hydrogen evolution rates of 1.8 μmol h-1, 0.55 μmol h-1 and 0.48 μmol h-1, respectively. The sample with x = 0.9 has a band gap of 2.82 eV, but did not evolve hydrogen. An extended photocatalytic test showed considerable reduction of activity over 20 hours.
PHOTOCATALYSIS OF ZINC SULFIDE MICROCRYSTALS IN REDUCTIVE HYDROGEN EVOLUTION IN WATER/METHANOL SYSTEMS
Yanagida, Shozo,Kawakami, Hiroshi,Hashimoto, Kazuhito,Sakata, Tadayoshi,Pac, Chyongjin,Sakurai, Hiroshi
, p. 1449 - 1452 (1984)
In photocatalytic H2 evolution using an aq. methanol system, high quality microcrystalline (cubic) ZnS powders have been found to be active under an appropriate light intensity, which is comparable in activity with freshly prepared ZnS suspensions.Compari
A method for covering a substrate with highly-oriented single crystalline hexagonal zinc structures under ambient pressure and room temperature
Cho, Seungho,Kim, Hye-Jin,Lee, Kun-Hong
, p. 6053 - 6055 (2009)
We report a novel method for covering a substrate with highly-oriented single crystalline hexagonal zinc structures under atmospheric pressure and room temperature without an external source of electric current, any templates or the use of epitaxial growt
Morphological evolution in zinc electrodeposition
Kahanda,Tomkiewicz
, p. 1497 - 1502 (1989)
We present an experimental study of the electrodeposition of zinc in a thin layer, three-electrode electrochemical cell. We show that as the steady-state current-potential behavior approaches mass transfer limited kinetics, the fractal dimension of the morphology of the deposit converges to the DLA value of 5/3. We also compare the evolution of the growth patterns with and without supporting electrolyte.
Breisch, K.
, p. 13 - 23 (1924)
Tunable Light Emission through the Range 1.8-3.2 eV and p-Type Conductivity at Room Temperature for Nitride Semiconductors, Ca(Mg1- xZn x)2N2 (x = 0-1)
Tsuji, Masatake,Hiramatsu, Hidenori,Hosono, Hideo
, p. 12311 - 12316 (2019)
The ternary nitride CaZn2N2, composed only of earth-abundant elements, is a novel semiconductor with a band gap of ~1.8 eV. First-principles calculations predict that continuous Mg substitution at the Zn site will change the optical band gap in a wide range from ~3.3-1.9 eV for Ca(Mg1-xZnx)2N2 (x = 0-1). In this study, we demonstrate that a solid-state reaction at ambient pressure and a high-pressure synthesis at 5 GPa produce x = 0 and 0.12 and 0.12 1-xZnx)2N2 converts its highly resistive state to a p-type conducting state. Particularly, the x = 0.50 sample exhibits intense green emission with a peak at 2.45 eV (506 nm) without any other emission from deep-level defects. These features meet the demands of III-V group nitride and arsenide/phosphide light-emitting semiconductors.
Electrochemical synthesis of zinc nanoparticles via a metal-ligand- coordinated vesicle phase
Gao, Yue,Hao, Jingcheng
, p. 9461 - 9471 (2009)
Two salt-free Zn2+-ligand-coordinated vesicle phases were prepared from the mixtures of alkyldimethylamine oxide (CnDMAO, n) 14 and 16, i.e., C14DMAO and C16DMAO) and zinc laurate [(CH3(CH2)10/s
New route for the synthesis of boron suboxide B7O
Liu,Zhao,Hou,Su
, p. L7-L9 (1995)
Boron suboxide B7O is synthesized with the aid of the oxidation of boron with zinc oxide ZnO under extreme conditions of high pressure, 3.50 GPa and high temperature, 1200 °C, and characterized by means of X-ray powder diffraction. This new rou
Synthesis and thermal characterization of zinc(II) di(o-aminobenzoate) complexes of imidazole and its methyl derivatives
Olczak-Kobza
, p. 67 - 71 (2004)
Mixed complexes of the type: Zn(Han)2(Him)3, Zn(Han)2(Him)5, Zn(Han)2(4-MeHim)2 and Zn(Han)2(1,2-diMeim)2 (where Han: NH2C 6H4COO
Electrocrystallisation of zinc from acidic sulphate baths; A nucleation and crystal growth process
Vasilakopoulos,Bouroushian,Spyrellis
, p. 2509 - 2514 (2009)
The electrochemical nucleation and growth of zinc on low-carbon steel from acidic (pH 2.0-4.5) baths containing ZnSO4, NaCl, and H3BO3, was studied by means of chronoamperometry at various cathodic potentials under a charg
Chromate conversion coatings formation on zinc studied by electrochemical and electrohydrodynamical impedances
Magalhaes,Tribollet,Mattos,Margarit,Barcia
, p. B16-B25 (2003)
The formation of chromate conversion coatings on zinc was studied by chronopotentiometric, electrochemical, and electrohydrodynamic impedances, and interfacial pH measurements. The electrochemical experiments were performed with a rotating disk electrode of pure zinc, and the pH measurements were obtained with a zinc deposit on a gold grid electrode in a submerged impinging jet cell. The electrolyte was an industrial chromate bath. The experimental results were achieved for different immersion times, temperatures, and rotation speeds. Kinetic reactions and physical model for the chromate layer formation on zinc were proposed, and the electrochemical and electrodynamic impedances were well simulated.
Clark, G. L.,Pish, G.,Weeg, L. E.
, p. 193 - 200 (1944)
Electrochemical preparation of porous copper surfaces in zinc chloride-1-ethyl-3-methyl imidazolium chloride ionic liquid
Lin, Yi-Wen,Tai, Chia-Cheng,Sun, I-Wen
, p. D316-D321 (2007)
The preparation of porous copper or copper-zinc surfaces by electrochemical formation of binary Cu-Zn alloys on Cu substrate and subsequent electrochemical etching of the zinc was investigated in a zinc chloride-1-ethyl-3- methylimidazolium chloride ionic liquid at 120°C. Cyclic voltammetry and X-ray diffraction measurements suggested that phase transformation from γ - to Β′ - Cu-Zn alloy occurred during constant potential dealloying. Essentially all the Zn content in the Cu-Zn could be removed from the alloy with dealloying at a sufficiently positive potential. Dealloyed materials exhibited well-developed bicontinuous porous structure. The dependence of the surface morphology of the porous Cu film on several experimental parameters, including deposition current and charge, and anodizing potential and temperature, were examined.
High-temperature decomposition of B-site-ordered perovskite Ba(Zn 1/2W1/2)O3
Jancar, Bostjan,Bezjak, Jana,Davies, Peter K.
, p. 758 - 764 (2010)
The reactions during high-temperature decomposition of Ba(Zn 1/2W1/2)O3 double perovskite, a potential microwave dielectric material, were studied by using X-ray diffraction, electron microscopy, and Knudsen effusion combined with mass spectrometry. The results show that above 1200°C, the perovskite decomposes due to the sublimation of ZnO, which results in the formation of BaWO4, Ba2WO 5, and amorphous BaO-rich phases. The simultaneous presence of BaWO4 and Ba2WO5 causes the formation of a liquid phase above 1320°C, which in the case of ceramics results in a progressive deterioration of the microstructure. As a consequence, the dielectric losses of Ba(Zn1/2W1/2)O3-based ceramics strongly depend on the processing parameters.
Zn electrodeposition in the presence of surfactants. Part I. Voltammetric and structural studies
Gomes,da Silva Pereira
, p. 863 - 871 (2006)
The zinc electrodeposition onto steel substrates in the presence of surfactants with different charged head groups, namely anionic sodium dodecylsulphate (SDS), cationic dodecyltrimethylammonium bromide (CTAB), and non-ionic octylphenolpoly(ethyleneglycolether)n, n = 10 (Triton X-100) was studied by cyclic voltammetry. The effect of the switching potential and scanning rate on the deposition process was investigated. The structural characterisation and the chemical composition of the samples prepared potentiostaticaly, in the potential range where the voltammetric cathodic peaks appear, was performed by X-ray powder diffraction (XRD) and by energy-dispersive X-ray analysis (EDS), respectively. The experimental results show that the voltammetric behaviour, namely the deposition potential depends on the presence, nature and concentration of the tested surfactants. Zn deposition occurs at potential values more positive than the estimated equilibrium potential, peak C1, simultaneously with hydrogen formation. This fact is confirmed by XRD measurements. Zn bulk deposits prepared in the absence of surfactants and in the presence of SDS are more crystalline and with a higher grain size than the ones obtained in the presence of CTAB and Triton X-100. These facts may be justified by an increase on the overpotential deposition as the electrochemical study confirms.
Schaffer, G. B.,McCormick, P. G.
, p. 45 - 46 (1989)
Trimetallic borohydride Li3MZn5(BH4) 15 (M = Mg, Mn) containing two weakly interconnected frameworks
Cerny, Radovan,Schouwink, Pascal,Sadikin, Yolanda,Stare, Katarina,Smrcok, L'Ubomir,Richter, Bo,Jensen, Torben R.
, p. 9941 - 9947 (2013)
The compounds, Li3MZn5(BH4)15, M = Mg and Mn, represent the first trimetallic borohydrides and are also new cationic solid solutions. These materials were prepared by mechanochemical synthesis from LiBH4, MCl2 or M(BH4) 2, and ZnCl2. The compounds are isostructural, and their crystal structure was characterized by in situ synchrotron radiation powder X-ray and neutron diffraction and DFT calculations. While diffraction provides an average view of the structure as hexagonal (a = 15.371(3), c = 8.586(2) A, space group P63/mcm for Mg-compound at room temperature), the DFT optimization of locally ordered models suggests a related ortho-hexagonal cell. Ordered models that maximize Mg-Mg separation have the lowest DFT energy, suggesting that the hexagonal structure seen by diffraction is a superposition of three such orthorhombic structures in three orientations along the hexagonal c-axis. No conclusion about the coherent length of the orthorhombic structure can be however done. The framework in Li 3MZn5(BH4)15 is of a new type. It contains channels built from face-sharing (BH4)6 octahedra. While X-ray and neutron powder diffraction preferentially localize lithium in the center of the octahedra, thus resulting in two weakly interconnected frameworks of a new type, the DFT calculations clearly favor lithium inside the shared triangular faces, leading to two interpenetrated mco-nets (mco-c type) with the basic tile being built from three tfa tiles, which is the framework type of the related bimetallic LiZn2(BH 4)5. The new borohydrides Li3MZn 5(BH4)15 are potentially interesting as solid-state electrolytes, if the lithium mobility within the octahedral channels is improved by disordering the site via heterovalent substitution. From a hydrogen storage point of view, their application seems to be limited as the compounds decompose to three known metal borohydrides.
Karschulin, M.,Ban, S.
, p. 244 - 247 (1940)
Ductility and crystallographic structure of zinc foils electrodeposited from acid zinc sulfate solutions
Ye,Celis,De Bonte,Roos
, p. 2698 - 2708 (1994)
A study of the relation between electrodeposition process parameters, structure and ductility of electrodeposited zinc foils was carried out. A stretching test was used to determine the ductility of zinc coatings after stripping them from the substrate. Depending on the relative texture coefficient coatings appeared to be more or less ductile. A loss of ductility when the pH of the electrolyte exceeds 4, was identified as due to zinc hydroxide precipitates. These particulates precipitate at the cathode and/or at the anode, then are transferred to the vicinity of the cathode where they can be codeposited with zinc.
Fabrication of a nanometric Zn dot by nonresonant near-field optical chemical-vapor deposition
Kawazoe, Tadashi,Yamamoto, Yoh,Ohtsu, Motoichi
, p. 1184 - 1186 (2001)
We demonstrate a technique for the deposition of nanometric Zn dots by photodissociation of gas-phase diethylzinc using an optical near field under nonresonant conditions. The observed deposited Zn dot was less than 50 nm in size. The photodissociation mechanisms are based on the unique properties of optical near fields, i.e., enhanced two-photon absorption, induced near-field transition, and a direct excitation of the vibration-dissociation mode of diethylzinc.
Density functional theory/B3LYP study of nanometric 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide complexes: Quantitative structure–activity relationship, docking, spectral and biological investigations
Saad, Fawaz A.,Elghalban, Marwa G.,El-Metwaly, Nashwa M.,El-Ghamry, Hoda,Khedr, Abdalla M.
, (2017)
New metal ion complexes were isolated after coupling with 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (H2L) drug ligand. The structural and molecular formulae of drug derivative and its complexes were elucidated using spectral, analytical and theoretical tools. Vibrational spectral data proved that H2L behaves as a monobasic bidentate ligand through one nitrogen from azo group and ionized hydroxyl oxygen towards all metal ions. UV–visible and magnetic moment measurements indicated that Fe(III), Cr(III), Mn(II) and Ni(II) complexes have octahedral configuration whereas Cd(II), Zn(II) and Co(II) complexes are in tetrahedral form. The Cu(II)complex has square planar geometry as verified through electron spin resonance essential parameters. X-ray diffraction data indicated the amorphous nature of all compounds with no regular arrangement for the solid constituents during the precipitation process. Transmission electron microscopy images showed homogeneous metal ion distribution on the surface of the complexes with nanometric particles. Coats–Redfern equations were applied for calculating thermo-kinetic parameters for suitable thermal decomposition stages. Gaussian09 and quantitative structure–activity relationship modelling studies were used to verify the structural and biological features. Docking study using microorganism protein receptors was implemented to throw light on the biological behaviour of the proposed drug. The investigated ligand and metal complexes were screened for their in vitro antimicrobial activities against fungal and bacterial strains. The resulting data indicated that the investigated compounds are highly promising bactericides and fungicides. The antitumour activities of all compounds were evaluated towards human liver carcinoma (HEPG2) cell line.
Ultrasonic assisted preparation of some new zinc complexes of a new tetradentate Schiff base ligand: thermal analyses data, antimicrobial and DNA cleavage potential
Akbari, Zahra,Montazerozohori, Morteza,Hoseini, Seyed Jafar,Naghiha, Reza
, (2021/02/03)
A new tetradentate Schiff base ligand (L) (L = obtained by condensation reaction between triethylenetetraamine and (E)-3-(2-nitrophenyl)acrylaldehyde) and some of its zinc (II) complexes formulated as ZnLX2 in which X = halide/pseudohalide were synthesized and characterized by some physical and spectral techniques such as infra-red (IR), nuclear magnetic resonance (NMR), UV–Visible, microanalyses, and conductivity measurements. Among the complexes, zinc chloride, iodide, and nitrate complexes were also prepared as nanostructure powder under sonication conditions confirmed by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray analysis (EDAX). Moreover, zinc oxide nanoparticles were prepared by direct thermolysis of nanopowder of ZnLI2 complex under air atmosphere. Moreover, the thermal behaviors of the compounds were studied based on thermo-gravimetric (TG)/differential thermal gravimetric (DTG)/differential thermal analyses (DTA) analyses data under nitrogen atmosphere. Furthermore, antibacterial/antifungal activities of the ligand and its zinc complexes were screened by the well diffusion method against some bacteria and funguses. Ultimately, the DNA cleavage potential of the compounds was evaluated by gel electrophoresis technique.
Synthesis, Structural characterization, thermal, molecular modeling and biological studies of chalcone and Cr(III), Mn(II), Cu(II) Zn(II) and Cd(II) chelates
Diab, H. A.,El-Gamil, Mohammed M.,El-Nahass, Marwa N.,Fayed, Tarek A.,Gaber, M.
, (2020/07/13)
A number of new Cr(III), Mn(II), Cu(II) Zn(II) and Cd(II) chelates of (E)-3-(4-(dimethyl-amino)phenyl)-1-(pyridin-2-yl)prop-2-en-1-one were synthesized. The structures were elucidated by elemental and thermal analysis as well as spectral techniques (mass, IR, and electronic spectra) and magnetic measurements. The IR data suggested that the investigated chalcone acted as a bidentate ligand via the O and N atoms of the C[dbnd]O and C[dbnd]N groups, respectively. The spectral plus magnetic data revealed the formation of octahedral structures for all chelates while Cu(II) chelate has the square planar geometry. The kinetic and thermodynamic parameters of the thermal decomposition stages have been evaluated. Molecular orbital calculations have been performed to confirm the geometry of the isolated compounds. The in vitro antimicrobial activities of the chalcone and its metal chelates have been performed against some bacterial strains. The data indicated that all the metal chelates demonstrated a higher activity than the free chalcone. The anticancer activity of the mentioned metal chelates is evaluated against MCF7 cell. These compounds exhibited a moderate and weak activity against the tested cell line. The results were correlated with the experimental data.