Xi:Irritant;
7440-22-4Relevant articles and documents
Chemical vapor deposition of silver films for superconducting wire applications
Shapiro,Lackey,Haruigofsky,Hill,Carter,Barefield
, p. 331 - 349 (1992)
Chemical vapor deposition (CVD) was used to deposit silver films for superconducting wire applications. AgI, silver trifluoroacetate (Ag(TFA)), and perfluoro-1-methylpropenylsilver (Ag(PF)) produced the most promising silver films. CVD processing was optimized on these three precursors using thermodynamic calculations performed using a modified version of the SOLGASMIX-PV computer program. Ag(PF) produced the highest quality silver films at low temperatures and pressures. A fiber tow which contained a silver barrier layer and a YBa2Cu3Ox overlayer was found to be a superconductor at 72 K.
Trimethylphosphite stabilized N-silver(I) succinimide complexes as CVD precursors
Tao, Xian,Wang, Yu-Long,Shen, Ke-Cheng,Shen, Ying-Zhong
, p. 169 - 171 (2011)
The preparation of [(MeO)3Pn?AgNC 4H4O2] (n = 1, 2a; n = 2, 2b) is described. The molecular structure of 2a was determined by using X-ray single crystal analysis. Complex 2b was tested as Metal Organic Chemical Vapor Deposition (MOCVD) precursor in the deposition of silver for the first time. The thin films obtained were characterized using scanning electron microscopy (SEM) and energy-dispersion X-ray analysis (EDX). SEM and EDX studies show that the dense and homogeneous silver films could be obtained.
Preparation and optical properties of silica@Ag-Cu alloy core-shell composite colloids
Zhang, Jianhui,Liu, Huaiyong,Wang, Zhenlin,Ming, Naiben
, p. 1291 - 1297 (2007)
The silica@Ag-Cu alloy core-shell composite colloids have been successfully synthesized by an electroless plating approach to explore the possibility of modifying the plasmon resonance at the nanoshell surface by varying the metal nanoshell composition for the first time. The surface plasmon resonance of the composite colloids increases in intensity and shifts towards longer, then shorter wavelengths as the Cu/Ag ratio in the alloy shell is increased. The variations in intensity of the surface plasmon resonance with the Cu/Ag ratio obviously affect the Raman bands of the silica colloid core. The report here may supply a new technique to effectively modify the surface plasmon resonance.
Thermal and MS studies of silver(I) 2,2-dimethylbutyrate complexes with tertiary phosphines and their application for CVD of silver films
Szymańska,Piszczek,Szczesny,Sz?yk
, p. 2440 - 2448 (2007)
[Ag2(CH3CH2C(CH3)2COO)2] (1), [Ag2(CH3CH2C(CH3)2COO)2(PMe3)2] (2) and [Ag2(CH3CH2C(CH3)2COO)2(PEt3)2] (3) were prepared and characterized by MS-EI; 1H, 13C, 31P NMR, variable temperature IR (VT-IR) spectroscopy and thermal analysis. MS and VT-IR data analysis suggests bidentate bridging carboxylates and monodentately bonded phosphines in the solid phase. The same methods used for gas phase analysis of 1-2 proved [(CH3CH2C(CH3)2COO)Ag2]+ as the main ion, which could be transported in the gas phase during the CVD process. In the case of 3, similar intensity to the latter ion revealed [Ag{P(C2H5)}]+ and it is responsible for the CVD performance of 3. Thermal analysis results revealed that decomposition of 1-3 proceed in one endothermic process, with metallic silver formation between 197 and 220 °C. In the case of 1, VT-IR studies of the gaseous decomposition products demonstrate the presence of ester molecules and CO2, whereas for 2 the main gaseous product appeared to be acid anhydride. Therefore, 2 was not used as a silver CVD precursor. Metallic layers were produced from 3 in hot-wall CVD experiments, (between 200 and 280 °C), under a total reactor pressure of 2.0 mbar, using argon as a carrier gas. Thin films deposited on Si(1 1 1) substrate were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Silver films obtained at moderate temperature (220-250 °C) revealed a thickness below 50 nm, and were whitish colored and slightly matt.
Thermal and chemical decomposition of di(pyrazine)silver(ii) peroxydisulfate and unusual crystal structure of a Ag(i) by-product
Leszczynski, Piotr J.,Budzianowski, Armand,Dobrzycki, Lukasz,Cyranski, Michal K.,Derzsi, Mariana,Grochala, Wojciech
, p. 396 - 402 (2012)
High purity samples of a [Ag(pyrazine)2]S2O 8 complex were obtained using modified synthetic pathways. Di(pyrazine)silver(ii) peroxydisulfate is sensitive to moisture forming [Ag(pyrazine)2](S2O8)(H2O) hydrate which degrades over time yielding HSO4- derivatives and releasing oxygen. One polymorphic form of pyrazinium hydrogensulfate, β-(pyrazineH+)(HSO4-), is found among the products of chemical decomposition together with unique [Ag(i)(pyrazine)] 5(H2O)2(HSO4)2[H(SO 4)2]. Chemical degradation of [Ag(pyrazine) 2]S2O8 in the presence of trace amounts of moisture can explain the very low yield of wet synthesis (11-15%). Attempts have failed to obtain a mixed valence Ag(ii)/Ag(i) pyrazine complex via partial chemical reduction of the [Ag(pyrazine)2]S2O8 precursor with a variety of inorganic and organic reducing agents, or via controlled thermal decomposition. Thermal degradation of [Ag(pyrazine) 2]S2O8 containing occluded water proceeds at T > 90 °C via evolution of O2; simultaneous release of pyrazine and SO3 is observed during the next stages of thermal decomposition (120-285 °C), while Ag2SO4 and Ag are obtained upon heating to 400-450 °C.
Structure and decomposition of the silver formate Ag(HCO2)
Puzan, Anna N.,Baumer, Vyacheslav N.,Mateychenko, Pavel V.
, p. 264 - 268 (2017)
Crystal structure of the silver formate Ag(HCO2) has been determined (orthorhombic, sp.gr. Pccn, a=7.1199(5), b=10.3737(4), c=6.4701(3)?, V=477.88(4) ?3, Z=8). The structure contains isolated formate ions and the pairs Ag22+ which form the layers in (001) planes (the shortest Ag–Ag distances is 2.919 in the pair and 3.421 and 3.716?? between the nearest Ag atoms of adjacent pairs). Silver formate is unstable compound which decompose spontaneously vs time. Decomposition was studied using Rietveld analysis of the powder diffraction patterns. It was concluded that the diffusion of Ag atoms leads to the formation of plate-like metal particles as nuclei in the (100) planes which settle parallel to (001) planes of the silver formate matrix.
Y2O3:Eu3+ (5 mol%) with Ag nanoparticles prepared by citrate precursor
Ferrari,Cebim,Pires,Couto Dos Santos,Davolos
, p. 2110 - 2115 (2010)
Y2O3:Eu3 (5 mol% Eu3) and Y2O3:Eu3 (5 mol% Eu3) containing 1 mol% of Ag nanoparticles were prepared by heat treatment of a viscous resin obtained via citrate precursor. TEM and EDS analyses showed that Y 2O3:Eu3 (5 mol% Eu3) is formed by nanoparticles with an average size of 12 nm, which increases to 30 nm when Ag is present because the effect of metal induced crystallization occurs. Ag nanoparticles with a size of 9 nm dispersed in Y2O 3:Eu3 (5 mol% Eu3) were obtained and the surface plasmon effect on Ag nanoparticles was observed. The emission around 612 nm assigned to the Eu3 (5D0→ 7F2) transition enhanced when the Ag nanoparticles were present in the Y2O3:Eu3 luminescent material.
Giles, J. K.,Salmon, C. S.
, (1923)
Brauner, B.
, p. 382 - 411 (1889)
PVP protective mechanism of ultrafine silver powder synthesized by chemical reduction processes
Zhang, Zongtao,Zhao, Bin,Hu, Liming
, p. 105 - 110 (1996)
Polyvinyl pyrrolidone (PVP) as a protective agent plays a decisive part in controlling superfine silver particle size and size distribution by reducing silver nitrate with hydrazine hydrate. The particle size and particle aggregation decrease with the PVP/AgNO3 mole ratio. Mechanisms of PVP protection were divided into three stages. First, PVP donates loan pair electrons of oxygen and nitrogen atoms to sp orbitals of silver ions, and thus the coordinative complex of Ag ions and PVP forms in aqueous solution. Second, PVP promotes the nucleation of the metallic silver because the Ag ions-PVP complex is more easily reduced by hydrazine than the pure Ag ions owing to Ag ions receiving more electronic clouds from PVP than from H2O. Third, PVP prohibits silver particle aggregation and grain growth as a result of its steric effect. All of the hypotheses were supported by ultraviolet spectra, infrared spectra, and heterogeneous nucleation and grain growth by addition of silver nuclei.
Molecules versus Nanoparticles: Identifying a Reactive Molecular Intermediate in the Synthesis of Ternary Coinage Metal Chalcogenides
Gahlot, Sweta,Jeanneau, Erwann,Singh, Deobrat,Panda, Pritam Kumar,Mishra, Yogendra Kumar,Ahuja, Rajeev,Ledoux, Gilles,Mishra, Shashank
, p. 7727 - 7738 (2020)
The identification of reactive intermediates during molecule-to-nanoparticle (NP) transformation has great significance in comprehending the mechanism of NP formation and, therefore, optimizing the synthetic conditions and properties of the formed products. We report here the room temperature (RT) synthesis of AgCuSe NPs from the reaction of di-tert-butyl selenide with trifluoroacetates (TFA) of silver(I) and copper(II). The isolation and characterization of a molecular species during the course of this reaction, [Ag2Cu(TFA)4(tBu2Se)4] (1), which shows extraordinary reactivity and interesting thermochromic behavior (blue at 0 °C and green at RT), confirmed that ternary metal selenide NPs are formed via this intermediate species. Similar reactions with related dialkyl chalcogenide R2E resulted in the isolation of molecular species of similar composition, [Ag2Cu(TFA)4(R2E)4] [R = tBu, E = S (2); R = Me, E = Se (3); R = Me, E = S (4)], which are stable at RT but can be converted to ternary metal chalcogenides at elevated temperature. Density functional theory calculations confirm the kinetic instability of 1 and throw light on its thermochromic properties.
Linear and nonlinear optical response of silver nanoprisms: Local electric fields of dipole and quadrupole plasmon resonances
Okada, Noriyuki,Hamanaka, Yasushi,Nakamura, Arao,Pastoriza-Santos, Isabel,Liz-Marzaì?n, Luis M.
, p. 8751 - 8755 (2004)
By means of femtosecond pump and probe spectroscopy, linear and nonlinear optical properties of silver nanoprisms have been investigated, focusing on enhancement of local electric fields due to dipole and quadrupole surface plasmons. Ag nanoprsims were prepared by direct reduction of AgNO3 by the solvent N,N-dimetnylformamide in the presence of poly(vinylpyrrolidone). The average edge length and thickness of the nanoprisms (triangles and truncated triangles) were 67 and 35 nm, respectively. In the absorption spectra, dipole and quadrupole plasmon resonance bands have been observed. The values of the imaginary part of nonlinear susceptibility Im??(3) measured at the dipole and quadrupole plasmon bands are -5.7 ?? 10-15 and -3.0 ?? 10-15 esu, respectively. The local electric field factors fQ and fD of quadrupole and dipole plasmon resonances were obtained from the observed dispersion curve of Im??(3) and absorption spectra, yielding a ratio fQ/fD of a??0.7. The nonlinear response times of both resonances were found to be a??2 ps, which is close to the value for spherical nanoparticles, indicating that the relaxation process via electron-phonon interaction is governed by bulk crystal properties.
Nanopowders of 3D AgI coordination polymer: A new precursor for preparation of silver nanoparticles
Bashiri, Robabeh,Akhbari, Kamran,Morsali, Ali
, p. 1035 - 1041 (2009)
Nanopowders of novel three-dimensional AgI coordination polymer, [Ag2(μ8-SB)]n (1) [H2SB = 4-[(4-hydroxyphenyl)sulfonyl]-1-benzenol] has been synthesized by the reaction of SB2- and AgNOsu
Rao, K. U. B.,Soman, R. R.,Singh, Haridwar
, p. 321 - 326 (1989)
Jagitsch, R.,Hedvall, J. A.
, p. 583 - 583 (1946)
Rossmanith, K.
, (1966)
Polymers or supramolecules generated from a new V-shaped bis-monodentate ligand and the effect of steric hindrance on coordination modes of the ligand
Zhou, Caihua,Wang, Yaoyu,Li, Dongsheng,Zhou, Lijun,Liu, Ping,Shi, Qizhen
, p. 2437 - 2446 (2006)
A new V-shaped bis-monodentate ligand L (L = 2,3′-dipyridylamine) (1) has been designed and synthesized by alkylation reaction of pyridylamine. An investigation of the charge distributions of the coordination atoms and single-point energy calculations of four conformers of ligand L based on the geometry of conformers optimized by the DFT (density functional theory) method was carried out. The results show that the four conformers of ligand L take on two stable and two less stable configurations. Theory forecasts that two relatively stable configurations present in complexes as probable coordination motifs of the ligand, and that steric hindrance of pyridine nitrogen atoms in isomers will affect its coordination ability together with the electronic factor. This forecast has been demonstrated by the coordination chemistry of ligand L, that is, configuration (a) and (b) of the ligand occur in the following reported complexes, which combines with AgI or Cu II through two coordination modes (bidentate bridging or a monodentate mode) resulting in coordination polymers {[Ag (L) 2]NO3}n (2), [Cu2(L) 2(maa)4]n (maa = methacrylic acid) (3), and the mononuclear molecule [Cu(L)4]-(ClO4)2· 2CH3CH2OH (4). The ligand assumes different coordination modes in the three complexes because of different levels of steric hindrance of the pyridine nitrogen atoms in the conformers. Interestingly, polymers 2 and 3 assume a 1D helical structure and a linear framework, respectively, and 4 has a 2D supramolecular architecture induced from hydrogen bond interactions. In addition, the magnetic properties of 3 have been explored, which shows a strong antiferromagnetic interaction. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Morphology-control in microwave-assisted synthesis of silver particles in aqueous solutions
Yamamoto, Tetsushi,Yin, Hengbo,Wada, Yuji,Kitamura, Takayuki,Sakata, Takao,Mori, Hirotaro,Yanagida, Shozo
, p. 757 - 761 (2004)
The morphologies of Ag particles can be controlled between distorted sphere and prism by employing microwave-promoted reductions of highly concentrated 0.1 M silver nitrate in aqueous solutions. Microwave (MW)-induced 1-min heating of aqueous solutions (≤ 0.1 M) of silver nitrate gave aggregates of sphere-nanoparticles in the presence of trisodium citrate (0.1-1.5 M) and excess of formaldehyde (1.5 M). Sample A1, prepared in the presence of an equal quantity (0.1 M) of trisodium citrate to silver nitrate, resulted in the formation of sphere-Ag particles with a smaller average particle size (24 nm) and a narrower particle size distribution (10-90 nm) than sample A2, prepared by the conventional heating (average size 71 nm, size distribution 20-360 nm). In addition to the MW effect, when the concentration of sodium citrate was increased, the inter-molecule hydrogen bonding of the citrate moieties associated with Ag particles should enhance the collision probability of the particles. Thus, large Ag particles with a wide particle distribution were produced in the presence of a larger amount of trisodium citrate under MW irradiation.
Straightforward green synthesis of "naked" aqueous silver nanoparticles
Giuffrida, Salvatore,Ventimiglia, Giorgio,Sortino, Salvatore
, p. 4055 - 4057 (2009)
Water-soluble, exceptionally stable, "naked" silver nanoparticles were obtained in a single step by simple decomposition of a commercial silver complex at room temperature without the need of external reducing agents and conventional stabilizing ligands.
Sawhney, S. S.,Kohli, Alka
, p. 217 - 220 (1982)
Transmetalation reaction between hydrophobic silver nanoparticles and aqueous chloroaurate ions at the air-water interface
Pasricha, Renu,Swami, Anita,Sastry, Murali
, p. 19620 - 19626 (2005)
The transmetalation reaction between a sacrificial nanoparticle and more noble metal ions in solution has emerged as a novel method for creating unique hollow and bimetallic nanostructures. In this report, we investigate the possibility of carrying out the transmetalation reaction between hydrophobic silver nanoparticles assembled and constrained at the air-water interface and subphase gold ions. We observe that facile reduction of the subphase gold ions by the sacrificial silver nanoparticles occurs resulting in the formation of elongated gold nanostructures that appear to cross-link the sacrificial silver particles. This transmetalation reaction may be modulated by the insertion of an electrostatic barrier in the form of an ionizable lipid monolayer between the silver nanoparticles and the aqueous gold ions that impacts the gold nanoparticle assembly. Transmetalation reactions between nanoparticles constrained into a close-packed structure and appropriate metal ions could lead to a new strategy for metallic cross-linking of nanoparticles and generation of coatings with promising optoelectonic behavior. ? 2005 American Chemical Society.
Investigation of silver-glass nanocomposites by positron lifetime spectroscopy
Mukherjee,Nambissan,Chakravorty
, p. 5649 - 5657 (1996)
Nanocrystalline silver particles were grown in a glass medium by ion-exchange and reduction techniques and studied by positron lifetime spectroscopy. The particle sizes varied from 5 to about 25 nm as observed by transmission electron microscopy. The positron lifetime spectra of all the samples could be decomposed into three components having lifetimes of around 160 ps, 400 ps and 1500 ps. The first is ascribed to positron annihilation at the interfaces of the nanocrystalline silver and the glass matrix, and it decreases and stabilizes as the silver grain size increases. The second component is explained as arising from positrons trapped and annihilated at the free-volume defects in the glass matrix. The third component arises because of the annihilation of orthopositronium at large free-volume defects. The effects of temperature on the interfacial defects and the processes leading to the formation of additional positron trapping centres are discussed.
Green and rapid synthesis of porous Ag submicrocubes via Ag3PO4 templates for near-infrared surface-enhanced Raman scattering with high accessibility
Hang, Lifeng,Wu, Yingyi,Zhang, Honghua,Xiang, Junhuai,Sun, Yiqiang,Zhang, Tao,Men, Dandan
, (2020)
Noble metal particles (Au and Ag) with porous structure are promising surface-enhanced Raman scattering (SERS) substrates, but their preparation processes are generally complex. Here, we report a remarkably facile, rapid and inexpensive method to synthesize two kinds of porous Ag submicrocubes, cage- and sponge-like submicrocubes with highly clean and accessible surfaces. These particles were synthesized in a completely green solvent (water) by using Ag3PO4 submicrocubes as templates at room temperature. Merely by optimizing the concentration of a reducing agent (NaBH4), three-dimensional cage- and sponge-like Ag submicrocubes were fabricated. As a result, as SERS substrates, the cage- and sponge-like Ag submicrocubes can achieve near-infrared (NIR)-SERS activity because they have broad absorption throughout the visible and NIR regions. Moreover, compared with the sponge-like Ag submicrocubes, cage-like submicrocubes with a highly rough surface had higher SERS enhancement due to the presence of narrow and deep nanoslits on their shells. Due to the high-density of ‘‘hot spots’’ produced by the narrow and deep nanoslits on the shell, cage-like Ag submicrocubes have a low SERS detection limit, 1.479 × 10?11 M for 4-aminothiophenol and 1.50 × 10?9 M for thiram. Thus, a new SERS substrate based on highly rough cage-like submicrocubes was obtained by an easy and green method.
Synthesis, characterization, and electrochemical properties of nanocrystalline silver thin films obtained by spray pyrolysis
Morales,Sanchez,Martin,Ramos-Barrado,Sanchez
, p. A151-A157 (2004)
Silver thin films were prepared using a spray pyrolysis method, silver acetate as the precursor, and stainless steel, heated at 225 and 300°C, as the substrate. Structural and morphological analyses carried out using X-ray diffraction, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy methods revealed the formation of highly homogeneous, porous coatings ca. 1 μm thick and with nanometric Ag particles as the main component. The presence of small amounts of Ag2O was also inferred from XPS data. The reduction process of these films, which are used as electrodes over the potential range 3.0-0.0 V in lithium cells, consisted of several steps involving the formation of a solid electrolyte interface between 1.5 and 0.2 V, and at least two Ag-Li alloys below 0.2 V, the patterns of which were indexed in the cubic and tetragonal systems, respectively. The alloying/dealloying processes are reversible, and the cell can deliver a capacity of 600 Ah kg-1 in the potential window 1.0-0.0 V.
Preparation of long silver nanowires from silver matrix by electron beam irradiation
Makita, Yoji,Ikai, Osamu,Ookubo, Akira,Ooi, Kenta
, p. 928 - 929 (2002)
Long silver nanowires with a high aspect ratio of up to 2000 could be obtained from Ag-containing matrix with NASICON structure by electron beam irradiation.
In situ synthesis of Ag/NiO derived from hetero-metallic MOF for supercapacitor application
Zhou, Lin-Xia,Yang, Yuan-Yuan,Zhu, Hong-Lin,Zheng, Yue-Qing
, p. 1795 - 1807 (2020/11/30)
Nanocomposite metal oxides have been attracted great attention in the electrode material of supercapacitor. Herein, a novel Ag/Ni hetero-metallic complex with the hamburger-like structure was prepared, which was then calcined to form Ag/NiO nanocomposite via in-situ preparation. The in-situ formed Ag/NiO exhibits a very high capacitance of 1480 F g ?1 at a current density of 0.6 A g?1 in 1?M KOH solution, and the cycling stability was retained about 85% after 3000 cycles with the current of 5 A g?1. The results showed that the in-situ formed Ag/NiO derived from hetero-metallic MOF possess high specific capacitance, which could provide a new effective strategy to improve the conductivity of metal oxides nanocomposite.
Spectroscopic studies, DFT calculations, thermal analysis, anti-cancer evaluation of new metal complexes of 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide
Emara, Adel A. A.,Mahmoud, Nelly H.,Rizk, Mariam G.
, (2021/08/06)
2-Hydroxy-N-(4-phenylthiazol-2-yl)benzamide was reacted with Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Ag(I) metal ions to synthesize the corresponding coordination compounds. From the study, 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide was rearranged to 2-hydroxy-N-(4-phenyl-1,3-thiazole-2-yl)carboxymidic acid (HL) due to the keto-enol tautomeric forms, where the enol form is more dominant. The structures of the HL ligand and the newly synthesized coordination compounds have been characterized by elemental analysis, IR, UV-Visible, 1H NMR, ESR and mass spectral data, in addition to thermal gravimetric analysis (TGA) and magnetic and molar conductance measurements. The ligand behaves as a monobasic bidentate ON sites, where the bidentate binding of the ligand involving the phenolic oxygen and azomethine nitrogen. The binding modes of the coordination compounds were further confirmed using Gaussian 09 software. The complexes of Co(II), Cu(II), Zn(II), and Ag(I) were tested in vitro against human colon carcinoma cells (HCT-116). The IC50 values showed dramatic toxicity results for cobalt(II), copper(II) and zinc(II) complexes versus human colon carcinoma (HCT-116) cell line, compared to African green monkey kidney (VERO) normal cell line. According to the results of the IC50 values obtained for Co(II), Cu(II), Zn(II), and Ag(I) 1.5, 1.0, 1.8 and 7.3 μg/ml, respectively, compared to the reference drug (2.49 μg/ml), Co(II), Cu(II), Zn(II) compounds are considered strong antitumor agent while Ag(I) compound can be considered as a weak one. For both antifungal and antibacterial activities, HL and all its coordination compounds were evaluated. HL ligand has only high activity against B. subtilis and C. albicans while Co(II) and Zn(II) compounds have the highest activity against S. aureus, P. aeruginisa, B. subtilis and E. coli.
