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1.
The optimum experimental conditions, with respect to sample and stripping solution composition, in computerised flow potentiometric stripping analysis for mercury(II) with a gold working electrode are described. When pre-electrolysis -was done in a sample to which ammonia and iodide had been added and stripping was done in an acidified bromide solution containing chromium(VI), a detection limit of 2 nM (0.4 μg kg-1) was obtained after 90 s of pre-electrolysis, the dynamic range being almost three decades. Copper(II) interfered when present in a 1000-fold excess and silver(I) when present in a 5-fold excess over mercury(II). 相似文献
2.
《Electroanalysis》2006,18(6):573-578
The electroanalytical detection of trace mercury(II) at gold ultra‐microelectrode arrays is reported. The arrays consist of 256 gold microelectrodes of 5 μm in diameter in cubic arrangements which are separated from their nearest neighbor by 100 μm. The array was utilized in nitric acid using linear sweep voltammetry where a linear response from mercury additions over the range 10 μg L?1?200 μg L?1 (10?8?10?6 M) was observed with a sensitivity and detection limit of 0.11 nC/μg L?1 and 3.2 μg L?1 (16 nM) respectively from using a deposition time of 30 s at ?0.2 V (vs. SCE). This methodology was explored in 0.1 and 1 M chloride media over the mercury range 10 μg L?1?200 μg L?1 (5×10?8?10?6 M) where similar sensitivities of 0.087 nC/μg L?1 and 0.078 nC/μg L?1 were observed with an identical detection limit. The protocol is demonstrated to be useful for the determination of mercury for analysis of environmental water samples. 相似文献
3.
N. V. Pervukhina G. V. Romanenko S. V. Borisov S. A. Magarill N. A. Palchik 《Journal of Structural Chemistry》1999,40(3):461-476
The crystal structures of 16 mercury(I)- and mercury(I, II)-containing minerals having (Hg-Hg)2+ groups are considered. The Hg-Hg and Hg-X bond lengths and the HgHgX angles (X = Cl, Br, I, O, S) are analyzed. A comparative crystal chemical analysis of the environment of Hg atoms is carried out. The Hg-Hg and Hg-X distances vary within 2.43-2.60 and 1.93-2.43 å, respectively; the angles defining the deviation of the X-Hg-Hg-X groups from linearity are from 146 to 177?. In most cases, the coordination environment of the mercury atoms involves the metal atom of the (Hg-Hg)2+ dumbbell and the X atom, but in several compounds the coordination number of the mercury atoms increases due to the additional atoms lying 2.5–3.5 å away. In terlinguaite and kuznetsovite, the Hg3 triangle is rather unusual; in the latter mineral, the Hg-Hg bonds are lengthened to 2.64-2.70 å. The review covers structural data up to May 1997. 相似文献
4.
Bis (α - diazophenacyl) mercury (2a), bis (α - diazo - 2,4,6 - trimethylphenacyl) mercury (2b), bis (1 - diazo - 3,3 - dimethyl - 2 - oxobutyl)mercury (2c), and bis (1 - diazo - 2 - phenylacetonyl) mercury (2d) have been prepared by treatment of the corresponding α-diazo ketones with mercuric oxide. The solution IR, UV, and 1H NMR spectra of 2a–d and of three other mercuribis (α-diazo ketones) have been compared with the spectra of the corresponding α-diazo ketones, and the similarities between these have led to the conclusion that in solution these mercury derivatives exist with the mercury bonded to carbon. The 13C NMR resonance spectra of 2a and of α-diazo - α - methylmercuriacetophenone (9) have been examined for evidence of 199HgC coupling; this was observed in the case of 9 for the Me carbon, but not detected in either case for the diazo carbon; this is attributed to difficulty of detection and/or ligand exchange. The signals of the diazo carbon in these spectra occur at unusually high field; a similar observation was made in the spectra of several α-diazo ketones, where the chemical shifts were in the range δ 50–70. 相似文献
5.
M. Olczak-Kobza 《Journal of Thermal Analysis and Calorimetry》1994,41(4):935-944
The processes of thermal decomposition of silver(I) and mercury(I) anthranilates and salicyloaldoximates were studied. Thermal, chemical and X-ray analyses and infrared spectroscopy were used to determine the mechanisms of decomposition of these complexes. The factor determining the decomposition is the character of the Ag+ and Hg 2 2+ ions, which are easily reduced to free metals. The final reaction product of the compounds of silver is the pure metal; the compounds of mercury are volatilized completely when heated. 相似文献
6.
Mohammad Albayer 《Journal of Coordination Chemistry》2019,72(8):1307-1321
AbstractWe report the synthesis and characterization of cationic Au(III) complexes supported by nitrogen-based ligands. The syntheses are achieved by reacting Au(I) complexes [Au(N-Me-imidazole)2]+ and [Au(pyridine)(NHC)]+ with iodine(III) reagents PhI(OTf)(OAc) and [PhI(pyridine)2]2+ yielding a series of cationic gold(III) complexes. In contrast, reactions of phosphine ligated gold(I) complexes with iodine(III) reagents results in the oxidation of the phosphine ligand. 相似文献
7.
Monomeric and Polymeric Dimethylaminothiosquarato Complexes: The Crystal Structures of Nickel(II), Cobalt(II), Silver(I), Platinum(II), Gold(I), Mercury(II) and Lead(II) Dimethylaminothiosquarates The ligand 2‐dimethylamino‐3, 4‐dioxo‐cyclobut‐1‐en‐thiolate, Me2N‐C4O2S− (L) forms neutral and anionic complexes with nickel(II), cobalt(II)‐, silver(I)‐, platinum(II)‐, gold(I)‐, mercury(II)‐ and lead(II). According to the crystal structures of seven complexes the ligand is O, S‐chelating in [Ni(L)2(H2O)2]·2 H2O, [Co(L)2(CH3OH)2] and (with limitations) in [Pb(L)2·DMF]. In the remaining compounds the ligand behaves essentially as a thiolate ligand. The platinum, gold and mercury complexes [TMA]2[Pt(L)4], [TMA] [Au(L)2] and [Hg(L)2] are monomeric. In [TMA][Ag2(L)3]·5.5 H2O a chain‐like structure was found. In the asymmetric unit of this structure eight silver ions, with mutual distances in the range 2.8949(4) to 3.1660(3)Å, are coordinated by twelve thiosquarato ligands. [Pb(L)2·DMF] has also a polymeric structure. It contains a core of edge‐bridged, irregular PbS4 polyhedra. TMA[Au(H2NC4O2S)2] has also been prepared and its structure elucidated. 相似文献
8.
Urine samples are treated with concentrated nitric acid and potassium permanganate ar 70°C for 10 min prior to injection. The flow electrode system consists of a 10-μm diameter gold fibre working electrode, a glassy carbon reference electrode and a platinum counter electrode. In the fully automated constant-current stripping procedure, the gold fibre is first covered with a fresh gold film after which the sample is electrolyzed for 1 min prior to stripping in 0.1 M hydrochloric acid with a current of 0.1μA. The procedure is repeated on a spiked sample after which the sample analyte concentrations are evaluated and presented digitally and graphically on a printer/plotter. The results obtained for bismuth, copper and mercury in a urine reference sample were 36.9, 39.7 and 47.7 μg l?1 with standard deviations (n=10) of 3.2, 4.2 and 2.1, respectively. The certified values for copper and mercury were 45 and 51 μg l?1; no certified value was available for bismuth. 相似文献
9.
Mixed ligand complexes of gold(I) with various selenones and Me3P, [Me3PAuSe=C<]Cl, have been prepared and characterized by elemental analyses, i.r. and n.m.r. methods. A decrease in the i.r. frequency
of the >C=Se mode of selenones upon complexation is indicative of selenone binding to gold(I) via a selenone group. An upfield shift in 13C-n.m.r. for the >C=Se resonance of selenones and downfield shifts in 31P-n.m.r. for Me3P moiety are consistent with the selenium coordination to gold(I). The steric effect as well as the basicity of Me3PAu+ plays a significant role in bonding with Se-containing ligands compared to the Et3PAu+ and Ph3PAu+ complexes. 相似文献
10.
Cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) can be determined by fastscan differential pulse polarography in methanolic acetate buffer solution at pH 5.6 at a hanging mercury drop electrode. At positive potentials, the insoluble salt formed between cyanuric chloride and mercury(I) is adsorbed on the mercury surface and the d.p.p. current is enhanced. The detection limit is 0.2gmg ml?1. Cyanuric chloride in air can be determined after absorption in methanol. 相似文献
11.
A novel approach to the electrochemical determination of heavy metals in tap water using anodic stripping voltammetry was developed using screen-printed electrodes modified with gold films. After optimisation of the experimental conditions, the screen-printed electrodes modified with gold films displayed excellent linear behaviour in the examined concentration range from 2 to 16 µg L-1 mercury and lead in 50 mM HCl with a detection limit of 1.5 µg L-1 and 0.5 µg L-1 for mercury and lead, respectively. In order to decrease the working range down to less than 1 µg L-1, a preconcentration step based on the use of magnetic particles modified with thiols was introduced into the protocol. Applying optimum binding conditions, the assay using screen-printed electrodes modified with gold films displayed excellent linear behaviour in the concentration range 0.1 to 0.8 µg L-1 in 50 mM HCl. The detection limit after a 120 s deposition time for mercury and lead were 0.08 µg L-1 and 0.02 µg L-1, respectively. The method has been applied to the determination of mercury and lead traces in tap water 相似文献
12.
It is critical to be able to detect and quantify Hg2+ ions under aqueous conditions with high sensitivity and selectivity. The technique presented herein provides a direct way for simple colorimetric visualization of Hg2+ ions in aqueous solution, based on the formation of gold nanoparticles through the Hg2+ catalyzed HAuCl4/NH2OH reaction. The outstanding selectivity and sensitivity result from the well-known amalgamation process that occurs between mercury and gold. The entire procedure takes less than 20 min. The limit of detection (2 ppb) shows excellent potential for monitoring ultralow levels of mercury in water samples. 相似文献
13.
Carolane M. Almeida Gabriel P. Nascimento Kelly G. Magalhães Bernardo A. Iglesias 《Journal of Coordination Chemistry》2018,71(4):502-519
The present study reports the synthesis and crystal structure of four novel gold(I) complexes with di-2-pyridyl ketone N(4)-ethylthiosemicarbazone (L1) and 2-acetylfuran-4-methyl-3-thiosemicarbazone (L2). All the gold(I) complexes were observed with monodentate thiosemicarbazones and exhibited gold(I) ions with linear geometries, bound to a sulfur atom of the ligand and a halogen ion (Br? or Cl?). The crystal structures of gold complexes with Br? and thiosemicarbazone are the first examples reported. Interestingly, 2[AuBr(HL1)]2Br was observed to have a Au?Au length of 3.155(8) Å, and this distance suggests an unusual Au?Au interaction in the solid state. The ability of the thiosemicarbazones and the corresponding gold(I) complexes to bind to DNA was studied by UV-vis and emission spectroscopy. The effect on cell viability of the compounds was evaluated against human breast cancer cell lines. The results show that the gold(I) complexes exhibit more potent inhibition of tumor growth than the free ligands. 相似文献
14.
The perchlorato ligand of perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) can easily be displaced by different types of ligands. Neutral complexes are obtained by adding anionic ligands (N?3, HCO?3, while cationic complexes are obtained by adding neutral monodentate ligands (OPPh3, OAsPh3, ONC5H5, ONC9H7, NC9H7, PEt3, PBu3, PPh2Me). Only with very weak σ-donors (SO2, CO2, NC5F5, NC5Cl5) does no reaction take place. The addition of neutral bidentate ligands leads to cationic gold(III) complexes with diphosphines and diarsines, whereas nitrogen- or oxygen-donors give rise to reductive elimination reactions which lead to gold(I) complexes.No reaction takes place with mono-olefins while cyclopolyolefins give rather unstable gold(I) complexes which readily decompose. Only the gold(I) complex with 1,5-cyclooctadiene can be isolated. 相似文献
15.
Coulometric generation of acetyl (CH3CO+) ions by oxidation of mercury in acetic anhydride and in acetic acid/acetic anhydride (5:95, v/v) is described. Current/potential curves for solvents, titrated bases, indicator and mercury showed that in both these solvents mercury is oxidized at potentials which are much more negative than those for the titrated bases and other components present in the solution. Quinoline, triethanolamine, triethylamine, pyridine and quinolin-8-ol in acetic anhydride, as well as triethylamine, 2,2′-bipyridine, 2,4,6-collidine, pyridine and sodium acetate in acetic acid/acetic anhydride were titrated with acetyl ions generated by the oxidation of mercury. In this way, it was established that the oxidation of mercury to mercury (I) ions proceeds quantitatively with 100% current efficiency. 相似文献
16.
A method for the rapid separation of copper(II) traces on metallic mercury is proposed. The separation is rendered possible by the reduction of Cu(II) to Cu(I) on mercury in the presence of iodide ions followed by the adsorption of the uncharged complex, Cu(I), on Hg0. After a minute of agitation, this adsorption is quantitative (90–100%) for initial concentrations of Cu(II) between 10?4 to 10?6 M and iodide cone, of 10?2 to 10?3 M at pH 3. The volumes of the aqueous solutions are of the order of 3–10 ml and those of the drops of mercury between 0.5–1 ml. The tests were made using the isotope 64Cu (T 1/2 = 12.8 h). 相似文献
17.
Enhanced Luminescent Properties of an Open‐Shell (3,5‐Dichloro‐4‐pyridyl)bis(2,4,6‐trichlorophenyl)methyl Radical by Coordination to Gold
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Yohei Hattori Dr. Tetsuro Kusamoto Prof. Dr. Hiroshi Nishihara 《Angewandte Chemie (International ed. in English)》2015,54(12):3731-3734
A gold(I) complex containing an open‐shell luminescent (3,5‐dichloro‐4‐pyridyl)bis(2,4,6‐trichlorophenyl)methyl (PyBTM) radical was prepared. The complex showed fluorescence centered mainly on the coordinated PyBTM ligand. The photophysical and photochemical properties were positively modulated upon coordination to AuI; the photoluminescence quantum yield, fluorescence wavelength, and the stability in the photoexcited state all increased. 相似文献
18.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1979,35(12):1359-1363
Infrared and Raman spectra are used to establish the regular trigonal bipyramidal (D3h) structure of [Co(CNC6H5]ClO4, [Co(CNC6H4 Cl-4)5]ClO4, and [Co(CNC6H2Me3-2,4,6)5]ClO4 in CH2Cl2 solution. Trigonal bipyramidal structure is also concluded for [Co(CNC6H2Me3-2,4,6)3-{P(OMe)3}2]BF4 and [Co(CNC6H2Me3-2,4,6)4P(OMe)3]BF4 in CH2Cl2 solution by interpretation of the proton-NMR, i.r., and Raman spectra; but [Co(CNC6H2Me3-2,4,6)4P(OMe)3]+ shows partial disproportionation into equdibrium concentrations of [CO(CNC6H2Me3-2,4,6)3{P(OMe)3}2]+ and [Co(CNC6H2Me3-2,4,6)5]+ which is characteristic of monosubstituted pentakis(arylisocyanide)cobalt(I) complexes with triphenylphosphite and triphenylphosphine. 相似文献
19.
Anna P. McLean Elizabeth A. Neuhardt Joel P. St. John Michael Findlater Colin D. Abernethy 《Transition Metal Chemistry》2010,35(4):415-418
(1,3-Bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)copper(I) chloride (1) was prepared by the reaction of 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride and copper(I) oxide in refluxing tetrahydrofuran.
In contrast to previously published methods of preparation of N-heterocyclic carbene complexes of copper(I) halides, this
synthesis requires neither an inert atmosphere nor scrupulously dry solvents. The structure of 1 was determined by elemental analysis, 1H and 13C NMR, and a single-crystal X-ray diffraction study. The X-ray crystal data reveal linear coordination about the copper(I)
center and linear chains of molecules formed with intermolecular head-to-tail C–H···Cl interactions. 相似文献
20.
M. M. Kamal Ali Z. Abu Zuhri Amna A. O. Nasser 《Fresenius' Journal of Analytical Chemistry》1996,356(8):500-503
The redox behaviour of adsorbed species of 2,4,6-tri(2′-pyridyl)-1,3-5-triazine (TPTZ) at the surface of a mercury electrode
was examined using cycling voltammetry. Based on the adsorption and accumulation of TPTZ at the charged mercury surface cathodic
adsorptive stripping voltammetry (CSV) is applied for the trace determination of TPTZ using a differential pulse (DP) technique.
Experimental and operational parameters for the quantitative analysis of TPTZ are optimized and the detection limit was found
to be 3×10−9 mol/l. The effect of some interferences, e.g. organic compounds, cations and anions, are investigated. 相似文献