Phenylmercury Chloride Research Articles

Metal organic framework assisted in situ complexation for miniaturized solid phase extraction of organic mercury in fish and Dendrobium officinale

Zirconium-based metal−organic frameworks, namely Zr-based MOF, was employed as adsorbent material in the miniaturized solid phase extraction of organic mercury compounds in food prior to capillary electrophoresis-diode array detector analysis. The synthesized adsorbent was characterized by different spectroscopic techniques. Parameters influencing the extraction and complexation of methylmercury chloride, ethylmercury chloride and phenylmercury chloride such as type of eluent solvent, type and amount of adsorbent were investigated. In addition, linear ranges contained 2.00–300.00 ng mL−1 for MeHg+, 5.00–500.00 ng mL−1 for EtHg+ and PhHg+, and the established method presented good linearity (R2 ≥ 0.998). Under the optimized experimental conditions, the ranges of detection limit and quantitation limit were 0.022–0.067 ng mL−1 and 0.073–0.220 ng mL−1, respectively. The relative standard deviations of intra- and inter-day analysis were less than 3.2 and 3.1%, respectively. Trueness of the present method was successfully accomplished by means of the recovery assays (81.4–98.5%) in the blank samples with two concentration levels. The repeatability %RSD of the method was lower than 2.7%. Overall, the developed approach proved to have the latent capability to be utilized in routine analysis of organic mercury compounds in fish and Dendrobium officinale.

Transmetalation of Pentafluorophenylmercury Derivatives with Organylmagnesium Bromides

The reactions of pentafluorophenylmercury derivatives with organomagnesium compounds have been studied. The interaction of pentafluorophenylmercury chloride with RMgBr (R = Et, Ph) has afforded diphenyl- and diethylmercury or phenylmercury chloride, besides the expected product (C6F5HgR). The results have been explained by the transmetalation of C6F5HgR with the Grignard reagent, followed by the reaction of the resulting C6F5MgX (X = Br, C6F5) with pentafluorophenylmercury chloride. Transmetalation of (C6F5)2Hg with organylmagnesium bromides has led to the formation of C6F5MgX and R2Hg.

The Construction of an Engineered Bacterial Strain and Its Application in Accumulating Mercury from Wastewater

To remove organic and inorganic mercury from wastewater, an engineered bacterial strain, BL21-7, was constructed that contained the artificial operon P16S-g10-merT-merP-merB1-merB2-ppk-rpsT. For BL21-7, the minimum inhibitory concentrations of mercuric chloride, methylmercury chloride and phenylmercury chloride in Luria-Bertani (LB) medium were 100 µmol/L, 60 µmol/L and 80 µmol/L, respectively. After being cultured in three media (liquid LB containing 80 µmol/L mercuric chloride, 40 µmol/L methylmercury chloride or 60 µmol/L phenylmercury chloride) for 72 h, the engineered bacteria accumulated up to 70.5 ± 1.5 µmol/L, 33.5 ± 3.2 µmol/L and 45.3 ± 3.7 µmol/L of mercury, respectively. In the presence of 10 µmol/L Cd2+, 10 µmol/L Pb2+ or 10 µmol/L Cu2+, the accumulation of mercurial derivatives by BL21-7 was not affected. BL21-7 could accumulate mercury well in media with pH values ranging from 5 to 8 and it could work well at temperatures from 25 °C to 37 °C. After BL21-7 was added to wastewater and cultured for 24 h, approximately 43.7% of the Hg in the wastewater was removed.

Electrochemistry and spectro-electrochemistry of dithizonatophenylmercury(II)

The reactions between dithizone (H2Dz, (1)) or potassium dithizonate (K+HDz−, (2)) and phenylmercury(II) chloride gives PhHg(HDz), (3). Complex (3) is photochromic. In dichloromethane, the blue photo-exited state of (3) exhibits a first order relaxation process to regenerate the orange ground state with rate constant 0.00053s−1. The half life of this relaxation is ca. 1300s. Electrochemically, on cyclic voltammetry time scale, the oxidations of (1) and (3) are different. A comparative voltammetric and spectro-electrochemical study of (1) and (3) in CH2Cl2 containing 0.1moldm−3 [N(nBu)4][B(C6F5)4] revealed that the mercapto group of (1) can be oxidised in two one-electron transfer steps. A disulphide is first produced and then in a second oxidation step, HDz+ is formed. In contrast, complex (3) shows only one ligand-based oxidation step. Upon complexation with phenylmercury the free mercaptan group of (1) becomes a stable “metal thioether”, Hg–S–C, which effectively prevents disulphide formation in (3) upon electrochemical oxidation. Both (1) and (3) shows two reduction steps. The electrochemical fingerprint of blue photo-excited (3) is identical to that of the orange ground state as no new functional groups are introduced upon irradiation; only bond rotation occurs. The different electronic spectra for each of the redox states of (3), obtained from spectro-electrochemical measurements, revealed that only the (3)/(3−) couple exhibits electrochromic properties.

ChemInform Abstract: Cyclometallation Reactions of 2-Phenylpyridine; Crystal and Molecular Structure of (2-(2-Pyridyl)phenyl)palladium(II) Tetramer and (2-(2-Pyridyl)phenyl)mercury(II) Tetramer.

Abstract The reaction of 2-phenylpyridine (HL) with palladium(II) compounds has been investigated. Cyclometallated and non-cyclometallated complexes may be obtained, dependent upon the reaction conditions. Cyclometallated derivatives are obtained directly by the reaction of HL with {Pd(OAc)2}3, by thermal reactions of monodentate N-bonded HL complexes, or by a transmetallation reaction with [{HgLCl}4]. The crystal and molecular structure of (2-{2-pyridyl}phenyl)palladium chloride tetramer (monoclinic, a=9.342(2), b=19.582(6), c=10.897(2) A, β=104.56(2)°, P21/c) has been determined, and is reported, together with that of (2-{2-pyridyl}phenyl)mercury chloride tetramer (monoclinic, a=10.334(2), b=7.484(1), c=27.052(6) A, β=97.60(2)°, P2t/n).

Complexation of Tolane by Fluorinated Organomercurials—Structures and Luminescence Properties of an Unusual Class of Supramolecular π-Coordination Polymers

The interaction of the Hg(II) derivatives bis(pentafluoro)phenyl mercury (1), (pentafluoro)phenyl mercury chloride (2) and trimeric perfluoro-ortho-phenylene mercury (3) with tolane (diphenylacetylene) in CH2Cl2 leads to the formation of [1·tolane], [2 2·tolane], and [3·tolane·CH2Cl2]. These adducts have been characterized by elemental analysis, X-ray crystallography, and luminescence spectroscopy. In the solid state of these adducts, the tolane molecules interact with the molecules of 1, 2 and 3 via secondary Hg–π interactions and arene–fluoroarene interactions. As a result of an external mercury heavy atom effect, adducts [1·tolane] and [2 2·tolane] are phosphorescent at room temperature.

Vapour generation at a UV/TiO2 photocatalysis reaction device for determination and speciation of mercury by AFS and HPLC-AFS

In this study we report a method for direct vapor generation of mercury species on nano TiO2 under UV irradiation in the presence of a formic acid and sodium formate mixture as a hole scavenger. A novelly designed UV/TiO2 photocatalysis reaction device (UV/TiO2 PCRD) was used as an effective sample introduction unit and an interface for mercury species determination by atomic fluorescence spectrometry (AFS) and speciation by HPLC-AFS for the first time. The detection limits of 10, 20, 30 and 70 pg mL � 1 of mercury chloride, methylmercury chloride, ethylmercury chloride and phenylmercury chloride, respectively, were achieved by AFS using flow injection mode. Compared with the traditional KBH4/NaOH-HCl system, UV/TiO2 PCRD is a superior alternative for online vapor generation of Hg species.

Diffusion pathways to critical cysteines in the vesicular acetylcholine transporter of Torpedo.

Previous work had demonstrated that organomercurial-mediated modification of two cysteine residues in the vesicular acetylcholine transporter (VAChT) from Torpedo californica inhibits binding of vesamicol. The cysteines are protected by acetylcholine and vesamicol (Keller et al. 2000. J. Neurochem. 74:1739-1748). Modified "cysteine 1" is accessible to glutathione from the cytoplasmic surface, whereas modified "cysteine 2" is not. Different organomercurials and aqueous environments were used here to characterize diffusion pathway(s) leading to the cysteines. para-Chloromercuriphenylsulfonate modifies VAChT much more slowly than do more hydrophobic p-chloromercuribenzoate and phenylmercury chloride. Permeabilization of vesicles with cholate detergent increases the rate of modification by p-chloromercuriphenylsulfonate. Permeabilization does not affect the ability of glutathione to reverse modification by p-chloromercuriphenylsulfonate. Higher ionic strength causes about four-fold increase in the rate of modification. The results suggest that hydrophobic and electrostatic barriers inhibit modification of Torpedo VAChT by negatively charged organomercurials and glutathione cannot reach cysteine 2 from either side of the membrane.

Speciation analysis of mercury in seafood by using high-performance liquid chromatography on-line coupled with cold-vapor atomic fluorescence spectrometry via a post column microwave digestion

An automatic system, based on the on-line coupling of high-performance liquid chromatography (HPLC) separation, post column microwave digestion, and cold-vapor atomic fluorescence spectrometry (CVAFS) detection, was proposed for the speciation analysis of four mercury compounds. Post column microwave digestion, in the presence of potassium persulfate (in HCl), was applied in the system to improve the conversion efficiency of three organic mercury compounds into inorganic mercury. Parameters influencing the on-line digestion efficiency and the separation effect were optimized. To avoid water vapor and methanol entering into the atomic fluorescence detector, ice–water mixture bath was used to cool the microwave-digested sample solution. Four mercury species including inorganic mercury chloride (MC), methylmercury chloride (MMC), ethylmercury chloride (EMC) and phenylmercury chloride (PMC) were baseline separated within 13 min by using RP C 18 column with a mobile phase of 50% (v/v) methanol containing 10 mmol l −1 tetrabutyl ammonium bromide and 0.1 mol l −1 sodium chloride pumped at 1.2 ml min −1. Seafood samples, composed of three gastropod species and two bivalve species from Yantai port, China, have been analyzed by the proposed method. Dogfish muscle (DORM-2) was analyzed to verify the accuracy of the method and the result was in good agreement with the certified value.

ChemInform Abstract: Phenylmercury Chloride: Its Single‐Crystal X‐Ray Structure and Some Aspects of Its Biological Chemistry.

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.

Phenylmercury Chloride: Its Single-Crystal X-Ray Structure and Some Aspects of its Biological Chemistry

A single crystal of phenylmercury chloride (PhHgCl) was obtained by serendipity from a solution of diphenylmercury (HgPh2) and dihydrolipoic acid in tetrahydrofuran / carbon tetrachloride. The crystal structure of PhHgCl is pseudotetragonal. It is best described in the orthorhombic space group Cmma with a = 6.856(1), b = 6.882(1), c = 14.309(2) Å (at 193 K), and Z = 4. The Cl-Hg-C moiety of the PhHgCl molecule is exactly linear. The bond lengths at the Hg atom are Hg-Cl 2.345(2) and Hg-C 2.044(9) Å. In the crystal, the molecules are arranged in double layers parallel to the a,b plane. In a model medium for the gastric juice (0.1 M DCl in D2O / [D8]dioxan, 37 °C), HgPh2 reacts to form PhHgCl. HgCl2, which would result from complete dearylation, cannot be isolated from the reaction mixture. However, it appears that a small equilibrium concentration of HgCl2 may be present, because on addition of 1,4,7-trithiacyclononane (ttcn) and diethyl ether, the dichloride can be trapped as solid [Hg(ttcn)2][HgCl4]. We estimate that after oral uptake of HgPh2 20 -90% are transformed into PhHgCl in the stomach after 30 min

Determination of total mercury in hydrocarbons and natural gas condensate by atomic fluorescence spectrometry

A new and simple technique for the determination of total mercury in gas condensate was developed which eliminates the use of chemicals/additives and complicated digestion procedures. The determinations are carried out by vaporisation of the samples at 400 °C with adsorption of mercury species on a gold trap (Amasil) maintained at 200 °C. The trap is then heated at 900 °C to release metallic mercury, which is determined by atomic fluorescence spectrometry. The mercury recoveries from seven species, dimethylmercury (DMM), diethylmercury (DEM), diphenylmercury (DPM), methylmercury chloride (MMC), ethylmercury chloride (EMC), phenylmercury chloride (PMC) and mercury(II) chloride (MC) spiked individually into gas condensate were found to be in the range 80–100%. The mercury recoveries for mixtures of the seven species added in equal amounts to gas condensate were in the range 88–97%. For Conostan mercury standard added to the condensate, the recovery was 88%. The instrumental precision from 10 measurements of a toluene control was 4% RSD. For three mercury species. DEM, MC and EMC, added to condensate, the precision was between 2 and 5% RSD (n = 10). The limit of detection (3ςn–1 criterion) for the procedure was calculated to be 180 pg Hg in toluene and 270 pg in condensate. For three mercury species added to a condensate sample, the absolute detection limits were 270 pg Hg for DEM, 450 pg Hg for MC and 630 pg Hg for EMC. Total mercury measurements in five real condensate samples from two sites at different stages of production covered the range 7–50 ng ml–1 with uncertainties in the range 4–7% RSD. The total mercury concentration of two commercial heavy gas oil samples were found to be 22.2 ± 0.6 µg ml–1 with RSD 3% (n = 4) and 2.3 ± 0.1 µg ml–1 of mercury with RSD 3% (n = 7).

Synthesis and NMR spectroscopy of dichlorobis (acetophenonethiosemicarbazone) mercury (II) formed from phenylmercury (II) chloride and acetophenonethiosemicarbazone: the first example of symmetrisation in organomercury (II)-thiosemicarbazone chemistry

The reaction of phenylmercury(II) chloride with acetophenonethiosemicarbazone (Hatsc) in ethanol in 1:1 mole ratio undergoes symmetrisation forming the products, HgCl 2(Hatse) 2 and Ph 2Hg instead of the anticipated compound PhHgCl(Hatse). The analytical data, some physical properties, IR and NMR ( 1H, 11C, 199Hg) spectroscopy all support the formation of HgCl 2(Hatse) 2, 199Hg NMR of the solid obtained from the filtrate of the reaction provides evidence for Ph 2Hg. This reaction represents the first example of a symmetrisation phenomenon observed in organomercury (II)-thiosemicarbazone chemistry.

ChemInform Abstract: Synthesis of Phenyl(perfluoroorgano)mercury Derivatives C6H5Hg(Rf) (Rf: CnF2n+1 (n = 1‐4 or 6) or C6F5) by the Reactions of Bis( perfluoroorgano)cadmium Compounds with Phenylmercury Chloride.

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.

Synthesis of phenyl(perfluoroorgano)mercury derivatives C 6H 5Hg(R f) [R f = C nF 2n + 1 ( n = 1–4 or 6) or C 6F 5] by the reactions of bis(perfluoroorgano)cadmium compounds with phenylmercury chloride

The mixed phenyl(perfluoroorgano)mercury derivatives C 6H 5Hg(R f) [R f = C nF 2n+1 ( n = 1–4 of 6), C 6F 5] have been prepared by reactions of C 6H 5HgCl with Cd(R f) 2 compounds, and their 19F NMR, 199Hg and (in some cases) 13C NMR spectra and mass spectra recorded.

On-line microwave sample pretreatment for the determination of mercury in water and urine by flow-injection cold-vapour atomic absorption spectrometry

A system for on-line treatment of liquid samples in a microwave oven and determination of mercury by cold-vapour atomic absorption spectrometry was designed and evaluated. The system consisted of an atomic absorption spectrometer, equipped with a mercury-hydride system and amalgamation accessory, a flow-injection system, an autosampler and a mircowave digestor. Urine and environmental water samples were stabilized with potassium dichromate-nitric acid and were mixed with a bromination reagent. The recoveries of eight mercury compounds from aqueous solutions and five compounds from dilute urine were studied. At an applied microwave power of 75 W, the recoveries of mercury(II) nitrate, methylmercury chloride, amidomercury chloride, phenylmercury chloride and diphenylmercury were between 92 and 102% for 1 + 2-diluted urine without amalgamation and between 94 and 111% for 1 + 5-diluted urine with amalgamation, respectively. The sample throughput was 30–40 h −1 without amalgamation and 24 h −1 in the amalgamation mode. Good agreement with certificate values was obtained for urine samples. A limit of detection (3σ) of 10 ng l −1 was obtained using 10-ml sample volumes of environmental waters (river, lake, rain) and the amalgamation technique. The results compared well with those from an external laboratory with correlation coefficients of 0.9302 and 0.9028 ( n = 22) for integrated absorbance and peak-height absorbance, respectively.

Determination of total mercury in human whole blood by electrothermal atomic absorption spectrometry following extraction

An electrothermal atomic absorption spectrometric based method is described for the determination of total mercury in human whole blood. The blood is first treated with dilute hydrochloric acid to free the mercury species bound to protein thiol groups, then a pH buffer and a complexing agent (diethyldithiocarbamate) are added and the mercury species are extracted into toluene. In initial experiments, total mercury was determined in the toluene extract by electrothermal atomic absorption spectrometry. Recoveries of methyl-, ethyl- and phenylmercury chloride and mercury(II) chloride added to blood were better than 95% at concentrations up to about 30 µg dm–3. However, problems with excessive background absorbance were frequently observed, which could be overcome by back-extraction into dilute hydrochloric acid; this modification being adopted in the proposed method. The accuracy of the method was confirmed by the determination of total mercury in three lyophilized, human whole blood samples (Seronorm), the results demonstrating good agreement with the reference values.

Enhancement effect of iron addition for the decomposition of organic mercury as studied by continuous flow analysis with cold vapor atomic absorption spectrometric detection

A continuous flow analysis is described for the determination of total mercury by cold vapor atomic absorption spectrometry. Organic mercury compounds such as methylmercury(II) chloride, ethylmercury(II) chloride and phenylmercury(II) chloride were decomposed by potassium peroxodisulphate with addition of ferric chloride as catalytic reagent. The reducing reagent used was tin(II) chloride in sodium hydroxide solution. With 1,000 mg Fe/l added in the decomposition process, we found that methylmercury(II) chloride and ethylmercury(II) chloride gave response signals similar to those of mercury(II) chloride. The proposed method was applied to the analysis of total mercury in waste water.

Metal exchange in organomercury complexes; a facile route to cyclometallated transition metal complexes

Cyclometallated derivatives of 2-phenylpyridine (HL) are readily obtained by transmetallation reactions of 2-(2′-pyridyl)phenylmercury(II) chloride, [Hg(L)Cl], with labile transition metal compounds. The products of these reactions are cyclometallated, containing metalcarbon bonds. The yields are high, and comparable with or better than those obtained from direct reactions with 2-phenylpyridine. The products are easily isolated, and are unequivocally metallated. The metal exchange reaction may be used to prepare cyclometallated complexes which are not available by direct reaction with 2-phenylpyridine. The use of the mercury(II) complex enables the use of kinetically inert chloro complexes in the transmetallation.

ChemInform Abstract: Palladium‐Catalyzed Intramolecular Arylation: A New Synthesis of Munduserone.

Abstract2H‐Chromene (I) reacts with phenylmercury(II) chloride and methanol to give the methoxyphenyl derivative (II).