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1.
The biomass of Aeromonas SH10 was proven to strongly absorb Ag+ and [Ag(NH3)2]+. The maximum uptake of [Ag(NH3)2]+ was 0.23 g(Ag) g−1(cell dry weight), higher than that of Ag+. Fourier transform infrared spectroscopy spectra analysis indicated that some organic groups, such as amide and ionized carboxyl in the cell wall, played an important role in the process of biosorption. After SH10 cells were suspended in the aqueous solution of [Ag(NH3)2]+ under 60°C for more than 12 h, [Ag(NH3)2]+ was reduced to Ag(0), which was demonstrated by the characteristic absorbance peak of elemental silver nanoparticle in UV-VIS spectrum. Scanning electron microscopy and transmission electron microscopy observation showed that nanoparticles were formed on the cell wall after reduction. These particles were then confirmed to be elemental silver crystal by energy dispersive X-ray spectroscopy, X-ray diffraction, and UV-VIS analysis. This study demonstrated the potential use of Aeromonas SH10 in silver-containing wastewater treatment due to its high silver biosorption ability, and the potential application of bioreduction of [Ag(NH3)2]+ in nanoparticle preparation technology.  相似文献   

2.
Two sol-gel fabrication processes were investigated to make silica spheres containing Ag nanoparticles: (1) a modified Stöber method for silica spheres below 1 m size, and (2) a SiO2-film formation method on spheres of 3–;7 m size. The spheres were designed to incorporate silver nanoparticles of high (3) in a spherical optical cavity structure for the resonance effect. For the incorporation, interaction between [Ag(NH3)2]+ ion and Si-OH was important. In the Stöber method, the size of the silica spheres was determined by a charge balance of plus and minus ions on the silica surface. In the film formation method, the capture of Ag complex ion on the silica surface depended on whether the surface was covered with OH groups or not. After doping [Ag(NH3)2]+ into silica particles or SiO2 films on the spheres, these ions w ere reduced by NaBH4 to form silver nanoparticles. From plasma absorption at around 420 nm wavelength and TEM photographs of nanometer-sized silver particles, their formation inside the spherical cavity structures was confirmed.  相似文献   

3.
Building on previous single crystal X‐ray structure determinations for the group 1 salts of complex thiosulfate/univalent coinage metal anions previously defined for (NH4)9AgCl2(S2O3)4, NaAgS2O3·H2O and Na4[Cu(NH3)4][Cu(S2O3)2]·NH3, a wide variety of similar salts, of the form , M1 = group 1 metal cation, M2 = univalent coinage metal cation (Cu, Ag), (X = univalent anion), most previously known, but some not, have been isolated and subjected to similar determinations. These have defined further members of the isotypic, tetragonal series, for M1 = NH4, M2 = Cu, Ag, X = NO3, Cl, Br, I, together with the K/Cu/NO3 complex, all containing the complex anion [M2(SSO3)4]7? with M2 in an environment of symmetry, Cu, Ag‐S typically ca. 2.37, 2.58Å, with quasi‐tetrahedral S‐M‐S angular environments. Further salts of the form , n = 1‐3, have also been defined: For n = 3, M2 = Cu, M1/x = K/2.25 or 1 5/6, NH4/6, (and also for the (NH4)4Na/4H2O·MeOH adduct) the arrays take the form with distorted trigonal planar CuS3 coordination environments, Cu‐S distances being typically 2.21Å, S‐Cu‐S ranging between 105.31(4)–129.77(4)°; the silver counterparts take the form for M1 = K, NH4. For n = 2, adducts have only been defined for M2 = Ag, the anions of the M1 = Na, K adducts being dimeric and polymeric respectively: Na6[(O3SS)2Ag(μ‐SSO3)2Ag(SSO3)]·3H2O, K3[Ag(μ‐SSO3)2](∞|∞)·H2O; a polymeric copper(I) counterpart of the latter is found in Na5Cu(NO3)2(S2O3)2 ≡ 2NaNO3·Na3[Cu(μ‐SSO3)2](∞|∞). For n = 1, NaAgS2O3, the an‐ and mono‐ hydrates, exhibit a two‐dimensional polymeric complex anion in both forms but with different contributing motifs. (NH4)13Ag3(S2O3)8·2H2O takes the form (NH4)13[{(O3SS)3Ag(μ‐SSO3)}2Ag], a linearly coordinated central silver atom linking a pair of peripheral [Ag(SSO3)4]7? entities. In Na6[(O3SS)Ag(μ‐SSO3)2Ag(SSO3)]·3H2O, the binuclear anions present as Ag2S4 sheets, the associated oxygen atoms being disposed to one side, thus sandwiching layers of sodium ions; the remarkable complex Na5[Ag3(S2O3)4](∞|∞)·H2O is a variant, in which one sodium atom is transformed into silver, linking the binuclear species into a one‐dimensional polymer. In (NH4)8[Cu2(S2O3)5]·2H2O a binuclear anion of the form [(O3SS)2Cu(μ‐S.SO3)Cu(SSO3)2]8? is found; the complex (NH4)11Cu(S2O3)6 is 2(NH4)2(S2O3)·(NH4)7[Cu(SSO3)4]. A novel new hydrate of sodium thiosulfate is described, 4Na4S2O3·5H2O, largely describable as sheets of the salt, shrouded in water molecules to either side, together with a redetermination of the structure of 3K2S2O3·H2O.  相似文献   

4.
Dissolution of solid AgNCO (silver isocyanate) in aqueous ammonia (25 %) and subsequent crystal growth at T = –9 °C furnished the new ammoniate (NH3)Ag(NCO) as colorless crystals [P21/c (no. 14); a = 4.1817(3) Å, b = 14.445(1) Å, c = 6.1988(5) Å, β = 102.0(4)°, V = 365,6(2) Å3; Z = 4]. In the molecular monammine complex, which is only stable at temperatures below T = 0 °C, silver is in a twofold, however, asymmetrical coordination by the isocyanate anion and ammonia. At the reaction conditions applied, AgNCO does not form an ionic diammine species (e.g. [Ag(NH3)2]+) as known from related silver salts. In this sense, the solvation chemistry of AgNCO exhibits a rarely observed feature.  相似文献   

5.
This article presents a facile method to prepare silver/polystyrene composite microspheres. In this approach, monodispersed polystyrene (PS) particles were synthesized with carboxyl acid groups on the surfaces of the PS particles via dispersion polymerization at first. With the addition of [Ag(NH3)2]+ to the PS dispersion, [Ag(NH3)2]+ was absorbed to the surfaces of the PS particles, and then by heating the system, [Ag(NH3)2]+ complex ions were reduced to silver to form the Ag/PS composite microspheres. In the synthesis of PS dispersion, PVP was used as dispersant to stabilize the PS particles, it also acted as reducing agent in the reduction of [Ag(NH3)2]+ complex ions to silver, so no additional reducing agent was needed. The resulting composite microspheres were characterized by TEM, SEM, XPS, and XRD. The catalytic properties and surface‐enhance Raman scattering (SERS) was studied as well. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4547–4554, 2009  相似文献   

6.
7.
The reaction of silver nitrate with sodium saccharinate (Na[sac]) in the presence of 2-pyridinepropanol in aqueous solution yields the title complex, Na[Ag(sac)2]. The compound crystallizes in the triclinic space group [a = 8.0481(6), b = 9.0587(6), c = 11.1642(8) Å; α = 100.064(3), β = 99.917(3) and γ = 92.367(3)°, Z = 2]. The structure consists of Na+ and [Ag(sac)2]- ions, in which each silver(I) ion is doubly bridged by the sac ligands, exhibiting a distorted 'T' shaped AgN2O coordination arrangement with one long [Ag-Osulfonyl = 2.6390(10) Å] and two shorter bonds [Ag-N = 2.1405(11) and 2.1570(11) Å]. The coordination around silver(I) is trigonal planar and the N-Ag-N bond angle is 158.99(5)°. The Na+ ion is five-coordinate with two carbonyl and three sulfonyl O atoms of the adjacent sac ligands and acts as a bridge between [Ag(sac)2]- units, resulting in a three-dimensional network. The i.r. spectra and thermal decomposition behaviour of Na[Ag(sac)2] are discussed in detail.  相似文献   

8.
Aromatic thiocarboxylic acids in presence of a base on treatment with silver nitrate under ambient conditions were oxidized to the corresponding disulfides. The reactions were found to be catalyzed by Ag+ ions. The catalytic oxidation is paralleled by the Ag(SCOAr) complex formation reaction which could be considerably subsided by adjustment of the reaction conditions. Attempts to use [Ag(PPh3)2]+ or [Ag(PPh3)]+ ion as the catalyst were unsuccessful as these resulted in the formation of the corresponding thiocarboxylate complexes. The products, ArCOSSCOAr (1, 2), [Ag(SCOAr)(PPh3)2] (3, 4) and [Ag(SCOAr)(PPh3)]4 (5) (Ar = C6H5, C4H3S) were characterized by single crystal X-ray analysis. Compounds 3 and 4 are monomeric while 5 is a cyclic tetramer in the crystalline phase.  相似文献   

9.
The reactivity of the monomeric N-heterocyclic carbene silver(I) complexes, 1,3-bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene-silver(I) chloride ([Ag(IMes)Cl], 1) and 1,3-bis-(4-bromo-2,6-dimethylphenyl)imidazol-2-ylidene-silver(I) chloride ([Ag(IMesBr)Cl], 2), toward the group 4 metal containing Lewis acids, TiCl4 and (η5-C5H5)ZrCl3, in dichloromethane was investigated. Instead of the expected transfer of the N-heterocyclic carbene to the Lewis acidic metal centers with accompanying precipitation of AgCl, chloride transfer occurred leading to the formation of the salts, [Ag(IMes)2]+[(TiCl3)22-Cl)3] (3) and [Ag(IMesBr)2]+[{(η5-C5H5)ZrCl}22-Cl)3] (4). The structure of the [Ag(IMesBr)2]+ cation in 4 is significantly distorted in the solid state by interactions between the para-Br atoms of the IMesBr ligands and chloride ligands of the anions.  相似文献   

10.
This article presents a facile method for the preparation of polystyrene/silver (PS/Ag) composite microspheres. In this approach, monodisperse PS spheres were synthesized via dispersion polymerization and modified by sulfonation to obtain sulfonated PS spheres with sulfonic acid groups on the surfaces, and then adsorbed Sn2+ ions by electrostatic interaction and used as templates. PS/Ag composite microspheres were prepared successively by addition of [Ag(NH3)2]+ complex ions to the templates dispersion, adsorbing to the surfaces of templates, and then reduction of [Ag(NH3)2]+ complex ions to Ag nanoparticles by sodium potassium tartrate. The results showed that monodisperse PS spheres with sulfonic acid groups on the surfaces were coated by an incomplete and nonuniform coverage of Ag nanoparticles in the absence of Sn2+ ions. In the presence of Sn2+ ions, however, complete and uniform Ag nanoparticles coatings were obtained on the entire PS sphere. And the deposition density and size of Ag nanoparticles can be controlled by [Ag(NH3)2]+ concentration. The resulting PS/Ag composite microspheres were characterized by SEM, TEM, XRD, TGA, and UV-vis. Preliminary catalytical tests indicated these PS/Ag composite microspheres showed good catalytic properties.  相似文献   

11.
Dark brown single crystals of [Ag(NH3)2]Ag(OsO3N)2 were obtained from the reaction of Ag2CO3, OsO4, and NH3 in aqueous solution. The crystal structure was solved in the monoclinic space group C2/m, with the following unit-cell dimensions: a=1962.5(3), b=633.1(1), c=812.6(1) pm, β=96.71(1)°. The final reliability factor was R=0.0256 for 1034 reflections with I>2σ(I). Linear [Ag(NH3)2]+ ions are present oriented perpendicular to the [010] direction, leading to short Ag+-Ag+ distances of 316 pm. A second type of Ag+ ions in the crystal structure present coordination number “6+1” and are surrounded by oxygen and nitrogen atoms of the nitridoosmate groups. Within the first of the two crystallographically distinguishable anions one can clearly differentiate between oxygen and nitrogen atoms while the second one exhibits a N/O disorder over two positions. The infrared spectrum of [Ag(NH3)2]Ag(OsO3N)2 shows the typical absorptions which can be attributed to the complex anions and the NH3 ligands.  相似文献   

12.
The syntheses and characterizations of homoleptic silver(I) carbene complexes of the type LAgCl (3) and [L2Ag]+2[Pd2Cl6]2− (4) (L=dimesityltetrahydropyrimid-2-ylidene) are described. 3 was obtained by reaction of the corresponding tetrahydropyrimidinium salt with silver(I) oxide. Subsequent reaction of 3 with Pd(CH3CN)2Cl2 afforded complex 4. The crystal structure of 3 has been determined to be a monomer in the solid state. The 13C NMR spectra of both 3 and 4 exhibit 13C-107,109Ag coupling in solution. Furthermore, both compounds show a downfield shift of the carbene carbon of about 20 ppm to about 205 ppm in the 13C NMR compared to five-membered ring silver(I) carbene complexes. Unlike other silver-carbene complexes, 3 does not undergo ligand exchange and can thus not be used for carbene transfer to other metals.  相似文献   

13.
[Ag(NH3)2]+ ions are chosen as an initial reaction precursor because of its simple displacement reaction and intrinsic arrangement as well as specific coordination directionality. Two new silver(I) ammine complexes, Ag2(NH3)HL2 ( 2 ) and Ag2(NH3)2HL3 ( 3 ), were obtained by a simple substitution reaction between [Ag(NH3)2]+ ions and pyridine‐4,5‐imidazoledicarboxylic acid [H3L2 = 2‐(3′‐pyridyl) 4,5‐imidazoledicarboxylic acid and H3L3 = 2‐(4′‐pyridyl) 4,5‐imidazoledicarboxylic acid]. Silver dimers are connected into a 2D layer and 1D chain in complexes 2 and 3 , respectively. In complex 2 two kinds of displacement reactions (mono‐substituting and bis‐substituting) occurred between the ammine molecules in [Ag(NH3)2]+ ions and H3L2, however, only the mono‐substituting reaction occurs in complex 3 .  相似文献   

14.
Silver nanoparticles preparation and the aggregation stability of the particles was investigated in lamellar liquid crystalline systems. A liquid crystal of HDTABr/pentanol/water was first prepared. The water content was next increased while keeping the mass ratio of HDTABr and pentanol constant. Silver nanoparticles were produced by replacing the aqueous phase by Ag sols of various concentrations (0.5–5×10–3 mol/l) or by an in situ preparation method, i.e., interlamellar reduction of Ag+ ions in the liquid crystalline phase. The stability of the silver nanoparticles was monitored by UV-VIS spectroscopy and TEM. The particle size ranged from 5 to 44 nm. The kinetic of silver nanoparticle aggregation was investigated. The effect of nanoparticles on structural ordering in liquid crystals was studied by XRD measurements and it was established that the lamellar distance (dL) was only slightly altered. Electronic Publication  相似文献   

15.
The oxidation of the [Fe(CO)4]2– dianion with Ag+ salts occurs through a particularinner-sphere mechanism, which involves an intermediate cascade of silver clusters stabilized by Fe(CO)4 ligands. The last detectable Ag-Fe cluster of the sequence is the [Ag13{-Fe(CO)4}8]3– trianion, which has been selectively obtained by using ca. 1.7 equivalents of Ag+ per mole of [Fe(CO)4]2–. The [Ag13{-Fe(CO)4}8]3–- trianion has been isolated in a crystalline state with several quaternary cations, and has been characterized by X-ray diffraction studies of its bis(triphenylphosphine)iminium salt. [N(PPh3)2]3 [Ag13{ 3-Fe(CO)4}8]·2(CH3)2CO, monoclinic, space group P21 (No.4),a = 16.284(2) Å,b =18.767(5) Å,c = 25.905(4) Å, = 90.46(1)°,V = 7916(3) Å3,Z = 2,R = 0.0324. The molecular structure of the anion consists of a centered cuboctahedron of silver atoms with the triangular faces capped by Fe(CO)4 units. Chemical reduction of ( Ag13{ 3-Fe(CO)4}8]3– affords the corresponding [Ag13{ 3-Fe(CO)4)8]4–, which in turn gives [Ag13{ 3-Fe(CO)4)8]5– and [Ag6{ 3-Fe(CO)4}4] upon further reduction. Electrochemical investigations confirm the reversibility of the [Ag13{ 3-Fe(CO)4}8]3–/4– redox change. Furthermore, in spite of some electrode poisoning effects, evidence of the existence of the [Ag13{ 3-Fe(CO)4}8]5– pentaanion was obtained. The yet structurally uncharacterized [Ag6{ 3-Fe(CO)4)4]2– dianion is quantitatively obtained by reaction of [Fe(CO)4]2– with ca. 1.5 equivalents of Ag+ or by addition of one equivalent of Ag+ to solutions of the [Ag5{Fe(CO)4}4]3– trianion. All attempts to isolate its quaternary salts as crystalline materials failed owing to formation of amorphous insoluble precipitates. The above series of 3-Fe(CO)4 octa-capped cuboctahedral Ag13 clusters can be envisioned as the Ag+ . Ag and Ag cryptates of the [Ag12{}3-Fe(CO)4}8]4– cryptand. respectively.Dedicated to Prof L. F. Dahl on his 65th birthday.  相似文献   

16.
Three new ionic silver complexes based on the 3,5-dimethyl-4-nitropyrazole ligand (HpzNO2) and 1:2 or 1:3 (Ag:HpzNO2) stoichiometries, [Ag(HpzNO2)2][BF4], [Ag(HpzNO2)3][SbF6] and [Ag(HpzNO2)3][PO2F2]·HpzNO2 have been prepared and structurally characterised. The linear or trigonal metallic coordination environment, the NO2 groups on the pyrazole ligand as well as the presence of counteranions of the type as , or (the latter one evolving to ) were strategically selected to produce molecular assemblies established on the basis of hydrogen-bonds (N-H?X) and π?π or coordinative interactions involving the NO2 group. The complex [Ag(HpzNO2)2][BF4] exhibited polymeric N-H?F hydrogen-bonded chains which were assembled in a 3D network by weaker coordinative Ag?O(NO2) and π(NO2)?π(NO2) interactions. In the complex [Ag(HpzNO2)3][SbF6], consistent with the three-coordinated molecular environment, the interactions were extended to give rise an open 3D cationic sub-network in which the counteranions were encapsulated. By contrast, in the related complex [Ag(HpzNO2)3][PO2F2]·HpzNO2 the presence of a fourth non-coordinated pyrazole HpzNO2 avoided the formation of a 3D network giving rise to a double-chained 1D structure.  相似文献   

17.
The literature known, but not fully characterized, silver dinitramide transfer reagents AgN(NO2)2 ( 1 ), [Ag(NCCH3)][N(NO2)2] ( 2 ), and [Ag(py)2][N(NO2)2] ( 3 ) have been investigated by 109Ag, 14N NMR and vibrational spectroscopy (IR, Raman). In addition, the poorly understood [Cu(NH3)4][N(NO2)2)]2 ( 4 ) and [Pd(NH3)4][N(NO2)2]2, ( 5 ) have also been prepared and characterized by 14N NMR and vibrational spectroscopy (IR, Raman). The structures of 2 — 5 have also been determined by X‐ray diffraction.  相似文献   

18.
19.
Four new silver(I) coordination polymers, namely [Ag(NH2pyz)(ox)0.5]n (1), [Ag(NH2pyz)(adp)0.5·2H2O]n (2), [Ag2(NH2pyz)2(bdc)·H2O]n (3) and [Ag2(NH2pyz)2.5(ndc)]n (4) [NH2pyz = 2-aminopyrazine, ox = oxalate anion, adp = adipate anion, bdc = 1,4-benzenedicarboxylate anion, ndc = 1,4-naphthalenedicarboxylate anion] have been synthesized by solution phase ultrasonic reactions of Ag2O with heterocyclic NH2pyz and various dicarboxylates under ammoniacal conditions. The complexes were characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction. Complex 1 is a three-dimensional (3D) framework with an α-ThSi2 topology. Complex 2 features a 2D 44-sql net involving infinite 1D double Ag-NH2pyz chains and flexible adp anion spacers. Complex 3 is a 3D framework in which 1D single Ag-NH2pyz chains are pillared by bdc anions to form a 2D 63-hcb network, adjacent 2D networks are packed into a 3D framework through bridging O atoms of dbc anions. Complex 4 is a 2D structure built from infinite 1D stair-like chains containing finite Ag4(NH2pyz)5 subunits. The results show that the structural diversity of the complexes result from the nature of the dicarboxylate ligands. The photoluminescence properties of the complexes were also investigated in the solid state at room temperature.  相似文献   

20.
A new palladium compound [Pd(NH3)4][cis-Pd(NH3)2(SO3)2][Pd(NH3)3(SO3)] · H2O (I) was synthesized and its structure was studied by X-ray powder diffraction method. In the course of the synthesis, the initial trans-diamminesulfite anionic complex is transformed into the cis-configuration. Further heating in aqueous solution results in isomerization of a substance into a neutral complex [Pd(NH3)3(SO3)]. Crystals I are triclinic: a = 10.3297(2) Å, b = 14.1062(3) Å, c = 6.8531(1) Å, = 101.36(0)°, = 92.74(0)°, = 92.71(0)°, space group P1¯. Structure I consists of the columns with alternating cis-[Pd(NH3)2(SO3)2]2– and [Pd(NH3)3(SO3)] complexes and [Pd(NH3)4]2+ ions between the columns.  相似文献   

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