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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 transformation of inorganic mercury (Hg) to methylmercury (MeHg) plays a key role in determining the amount of Hg that is bioaccumulated in aquatic food chains. An accurate knowledge of Hg methylation mechanisms is required to predict the conditions that promote MeHg production in aquatic environments. In this study, we conducted experiments to examine the oxidation and methylation of dissolved elemental mercury [Hg(0)] by the anaerobic bacterium Desulfovibrio desulfuricans ND132. Anoxic cultures of D. desulfuricans ND132 were exposed to Hg(0) in the dark, and samples were collected and analyzed for the loss of Hg(0), formation of non-purgeable Hg, and formation of MeHg over time. We found that D. desulfuricans ND132 rapidly transformed dissolved gaseous mercury into non-purgeable Hg, with bacterial cultures producing approximately 40 μg/L of non-purgeable Hg within 30 min, and as much as 800 μg/L of non-purgeable Hg after 36 h. Derivatization of the non-purgeable Hg in the cell suspensions to diethylmercury and analysis of Hg(0)-reacted D. desulfuricans ND132 cells using X-ray absorption near edge structure (XANES) spectroscopy demonstrated that cell-associated Hg was dominantly in the oxidized Hg(II) form. Spectral comparisons and linear combination fitting of the XANES spectra indicated that the oxidized Hg(II) was covalently bonded to cellular thiol functional groups. MeHg analyses revealed that D. desulfuricans ND132 produced up to 118 μg/L of methylmercury after 36 h of incubation. We found that a significant fraction of the methylated Hg was exported out of the cell and released into the culture medium. The results of this work demonstrate a previously unrecognized pathway in the mercury cycle, whereby anaerobic bacteria produce MeHg when provided with dissolved Hg(0) as their sole Hg source.

A method for mercury analysis and speciation in drinking water was developed, which involved stir bar sorptive extraction (SBSE) with in situ propyl derivatization and thermal desorption (TD)-GC-MS. Ten millilitre of tap water or bottled water was used. After a stir bar, pH adjustment agent and derivatization reagent were added, SBSE was performed. Then, the stir bar was subjected to TD-GC-MS. The detection limits were 0.01 ng mL(-1) (ethylmercury; EtHg), 0.02 ng mL(-1) (methylmercury; MeHg), and 0.2 ng mL(-1) (Hg(II) and diethylmercury (DiEtHg)). The method showed good linearity and correlation coefficients. The average recoveries of mercury species (n=5) in water samples spiked with 0.5, 2.0, and 6.0 ng mL(-1) mercury species were 93.1-131.1% (RSD11.5%), 90.1-106.4% (RSD7.8%), and 94.2-109.6% (RSD8.8%), respectively. The method enables the precise determination of standards and can be applied to the determination of mercury species in water samples.

Organic mercury compounds can be found in petroleum and natural gas products in very small concentrations. The knowledge of the thermodynamic properties of these compounds is important for the petroleum industry. Among the thermodynamic properties useful for industry, the solubilities of organic mercury compounds such as dimethylmercury (Hg(CH3)2) and diethylmercury (Hg(C2H5)2) in organic or aqueous solvents are important to be determined. Since experiments are difficult to perform due to the very high toxicity of these molecules, we developed a force field including electrostatic interactions to be able to obtain these properties by molecular simulation. Our results are in good agreement with the experimental data and also show a weak influence of the electrostatic part in the potential. This force field development enables us to obtain liquid−vapor equilibrium of mercury compound−light alkane mixture.

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).

This paper describes optimization details of an analytical method development of a hydride-generation procedure for speciation of mercury(II), monomethylmercury cation, dimethylmercury, and diethylmercury using a heated quartz furnace with an atomic absorption spectrophotometer (AAS) as a detector. Typically a new analytical method is developed in steps such as the following: (1) determining analytes individually to confirm retention times and the lack of decomposition during the procedure; (2) comparing peak areas of all analytes as a function of quartz furnace temperature to optimize atomization for AAS detection; (3) conducting factorial experiments to determine which hydride-generation reaction conditions are important in maximizing peak areas and which conditions interact with each other; (4) using the simplex optimization method to give final optimization of reaction conditions. These steps result in conditions that maximize optimized peak areas for analytes while minimizing experimental error.

Mercury(II), monomethylmercury cation (MeHg), dimethylmercury (Me 2 Hg) and diethylmercury (Et 2 Hg) were simultaneously determined from aqueous samples by hydride generation volatilization, trapping and separation on a chromatographic column, and detection by atomic absorption spectrophotometry in a heated quartz furnace. Simplex optimization showed us the most effective choice of hydride formation and purge conditions. Absolute detection limits are 50 pg for the three organomercury compounds and 110 pg for Hg(II). Calibration curves are linear from 0.05 to 5 ng, and the reproducibility range for 1 Hg of the four analytes is 3–7%. Large differences among measured MeHg concentrations in a recent interlaboratory study using different measurement methods confirm that a new, completely independent method for determining mercury compounds in environmental samples is important. The method was applied to estuarine samples of the marsh grass Spartina alterniflora and eelgrass ( Zostera marina L.) and found Hg(II), MeHg (eelgrass only) and Me 2 Hg. Our difficulties in determining Me 2 Hg suggest that it is more common in the aquatic environment than commonly believed.

Foi desenvolvida uma metodologia para quantificar compostos dialquilmercuricos usando Microextracao em Fase Solida em Headspace (HS-SPME) e Cromatografia Gasosa com Deteccao por Emissao Atomica (GC-AED). Os parâmetros para deteccao de Hg foram otimizados usando planejamento fatorial e superficies de resposta. Experimentos univariados foram empregados para determinar as condicoes de HS-SPME; as melhores fibras foram 75 Mm de Carboxen / PDMS e 65 Mm de PDMS / DVB. Porem, as primeiras foram descartadas pela extensa degradacao termica dos analitos na dessorcao. O procedimento otimizado permite detectar os analitos em amostras aquosas com limite de deteccao de 1,7 e 0,2 ng L -1 para dimetil- and dietilmercurio, respectivamente. As curvas analiticas sao lineares nas faixas de 36 a 180 ng L -1 (Me 2 Hg) e 38 a 190 ng L -1 (Et 2 Hg), com limite de quantificacao de 38 ng L -1 (Me 2 Hg) e 29 ng L -1 (Et 2 Hg) e coeficientes de correlacao de 0,998 para Me 2 Hg e 0,999 para Et 2 Hg. A methodology to quantify dialkylmercury compounds using Headspace Solid Phase Microextraction (HS-SPME) and Gas Chromatography with Atomic Emission Detection (GC-AED) was developed. The parameters for Hg detection were optimized by factorial design and response surfaces. Univariate experiments were employed to determine the HS-SPME conditions; 75 Mm Carboxen / PDMS and 65 Mm PDMS / DVB were the best fibers. However, the former was excluded from further experiments due to extensive thermal degradation of analytes during desorption. The optimized procedure allowed detection of the analytes from aqueous samples with LOD of 1.7 ng L -1 and 0.2 ng L -1 for dimethyl- and diethylmercury, respectively. The analytical curves are linear in the range from 36 to 180 ng L -1 (Me 2 Hg) and 38 to 190 ng L -1 (Et 2 Hg), with LOQ of 38 ng L -1 (Me 2 Hg) and 29 ng L -1 (Et 2 Hg) and correlation coefficients of 0.998 for Me 2 Hg and 0.999 for Et 2 Hg.

Mercury is emitted into the atmosphere from a number of natural as well as anthropogenic sources. Anthropogenic emissions of mercury are thought to be of the same order of magnitude as those from natural sources (Ebinghaus et al. 1998). In addition to elementary mercury in the atmosphere, dimethyl and diethylmercury, as well as particle-bound mercury have been detected in the very low pg/l concentration range (Kaiser and Tolg 1980).

A simple and fast method for the determination of arsenic (As) in sunflower oil by electrothermal atomic absorption (ETAAS) is described. The optimal instrumental parameters for ETAAS measurement of As species in stable and homogeneous soap emulsions prepared from oil samples with tetramethylammonium hydroxide (TMAH) have been established. The limit of determination is 5 ng x g(-1) total As in sunflower oil. A second approach involving extraction of As and mercury from sunflower oil and consequent ETAAS measurement is also described. Simultaneous quantitative extraction of As(III), As(V), monomethylarsonate (MMA) and dimethylarsinate (DMA) as well as Hg(II), monomethylmercury(II)chloride (MMC), dimethylmercury (DMM), diethylmercury (DEM) and diphenylmercury (DPM) is achieved by using an extraction mixture comprising of 0.1M NH3/0.01 M EDTA. Pre-reduced palladium is applied as an effective modifier for the next ETAAS measurement of all extracted species. The method of standard addition is employed for calibration. The accuracy and reproducibly of the methods was established by spike and recovery experiments and parallel analysis of sunflower oils from the marketplace. Limits of determination of 2 ng x g(-1) for As and 3 ng x g(-1) for mercury were obtained.

An automated, small and easily mountable/demountable accessory based on a constant temperature multicapillary GC is proposed for time-resolved introduction of gaseous mercury species into an ICP-MS. The fast, narrow-band injection was achieved by cryofocussing (–80 °C) of dimethyl-, methylethyl- and diethylmercury in an 11 cm capillary housed in a steel tube prior to desorption of the species (within 3–5 s) by rapid-pulse high intensity current. The highest chromatographic resolution was achieved at ambient column temperatures; isothermal separations at higher temperatures offered increased sensitivity and speed of analysis controlled by the data acquisition rate of a quadrupole MS. The compatibility of the operating variables with the ICP ionization conditions (argon at 50–300 ml as the carrier gas) and negligible peak broadening on the column and in the ICP-MS interface allow the sensitive (limit of detection 0.15 pg) isotope-selective speciation of mercury in biological and sediment samples.

A technique has been developed for the determination of dimethyl- and diethylmercury. It is based on the separation by reversed-phase HPLC, on-line decomposition of the dialkylmercury compounds by H2O2 and UV-irradiation, reduction with alkaline sodium borohydride, followed by gas liquid separation of mercury vapour and determination by cold vapour atomic absorption detection. The method permits the simultaneous determination of dimethyl- and diethylmercury by RP C18 HPLC-CVAAS. The limit of detection (S/N=3) for both compounds was calculated to be about 30 ppb.

Tris(pentafluorophenyl)germanethiol, (C6F5)3GeSH (Ia), was obtained in good yield by heating the tris(pentafluorophenyl)germane with elemental sulphur or by the exchange between Et3GeSH and (C6F5)3GeBr. The reaction between sulphur and (C6F5)2GeH2 or C6F5GeH3 gives heterocyclic products with chains of alternating germanium and sulphur atoms in the cycles. The compounds [(C6F5)3Ge]2X (X = S, Se) were prepared by exchange reaction of (Et3Ge)2X with tris(pentafluorophenyl)germanium bromide and by reaction of chalcogens (S8, Se8) with hexakis(pentafluorophenyl)digermane. Ia reacts with diethylmercury affording (C6F5)3GeSHgEt. Insertion of elemental sulphur into the GeHg bond of bis[tris(pentafluorophenyl)germyl]mercury led to the thermally stable (C6F5)3GeSHgGe(C6F5)3.

Alkylmercury compounds were preconcentrated from air on a Carbotrap (graphitized carbon black) column at room temperature. The species were then transferred by thermal desorption to a U-tube chromatographic column packed with 15% OV-3 on Chromosorb WAW-DMSC, held at −196°C in liquid nitrogen. The compounds were clearly separated and eluted in order of increasing polarity using a simple, ramped heating step to 180°C over 20 min. After thermal decomposition of the eluant, the resultant mercury vapour was detected by cold-vapour atomic fluorescence spectrometry. The detection limits (as Hg) for the system were approximately 0.3 pg for mercury and dimethylmercury, 0.4 pg for diethylmercury, and 2.0 pg for methylmercury chloride. A study of the Long Island Sound atmosphere showed Hg0 to account for 95–100% of the total mercury present, with the remainder being monomethylmercury.

1. A series of hydride complexes of nickel, palladium, and platinum was obtained by oxidative-addition reactions of zerovalent triphenylphosphine complexes of the metals with pentafluorophenyl-substituted germanes. The Pt-H groups in the obtained compounds were distinguished by low reactivity. 2. A stable complex with a Pt-Ge-Ge-Hg chain was synthesized by the reaction of HPt(PPh3)2-Ge(C6F5)2-Ge(C6F5)2H with diethylmercury.

Wistar rats were given CH 3 HgCl ( 203 Hg-labeled) and (CH 3 CH 2 ) 2 Hg in peanut oil intraperitoneally (5.0 mg/kg) every second day from 5 until 27 days of age. A reference group was given identical injections of oil only. The rats appeared normal throughout the experimental period. The brains of the three groups were subjected to subcellular fractionation and myelin, nerve-ending particles, mitochondria and microsomes were isolated. Protein, total mercury, inorganic mercury, succinic dehydrogenase and acetylcholinesterase were measured in the fractions. The two groups showed an equal mercury content in the brain and the subcellular distribution of mercury showed a correlation with the protein content. The succinic dehydrogenase activity of the mitochondrial fraction was considerably decreased in both mercury groups compared with the reference group. The myelin fraction contained 4 times as much inorganic mercury relative to total mercury compared with other fractions after CH 3 HgCl injections.

1. In the transition from inert solvents to solvating solvents, the internal chemical shift of the ethyl protons for ethyl protons for ethyl derivatives of silicon, germanium, tin, and mercury increases. 2. The donor activity of the solvents depends substantially on the nature of the acceptor. 3. The variation of the electronegativity of the elements of subgroup IV B: C (2.60)>Pb (2.10)>Ge (1.90)>Sn (1.84)>Si (1.82) does not agree with the arrangement of these elements in the Mendeleev periodic system. 4. The variation of the spin-spin interaction constant JCH2—199Hg for diethylmercury in various solvents depends chiefly on the change in the s-electron density on the protons.

Summary Aquodiethyllead(IV) ion undergoes a two-electron reduction at the dropping mercury electrode. E 1/2 is −0.37 V vs . SCE in acidic solution and becomes more negative with a slope of 25 mV/pH unit in neutral and alkaline buffers. The diradical initially formed decays rapidly by disproportionation to tetraethyllead and lead metal and by transmetallation to diethylmercury. Disproportionation is the major decay path over the accessible concentration range.

Ethylsodium has been prepared from sodium and diethylmercury and, using a new method, from sodium tert-butoxide and ethyllithium. The crystal structure of rhombohedral ethylsodium has been determined from X-ray powder data (space groupR 3 m; unit cell constants using hexagonal axes: a = 4.53 A, c = 28.24 A; Z = 6). Rhombohedral ethylsodium is built up by double-layers. The outer portions of each layer contain ethyl groups, arranged perpendicular to the plane. The CH2 groups are oriented towards the inner part of the layer and are surrounded by Na ions in a trigonal-pyramidal array (co-ordination 1 + 3; NaC distances 2.68 and 2.63 A. respectively). Under different conditions the reaction of sodium tert-butoxide and ethylsodium yields a cubic modification (a = 28.003 A) of unknown structure.

The action of 1,3-bis(diethylgermyl)propane or 1,4-bis(diethylgermyl)butane on diethylmercury leads to a mercury derivative which by pyrolysis gives a cyclic compound with two adjacent intracyclic germanium atoms. The five-membered ring derivative easily reacts with oxygen, sulfur and selenium giving the corresponding six-membered ring heterocycles by a ring expansion reaction. The six-membered ring derative, which is much less reactive, does not appreciably react under the same experimental conditions. The two types of digermacycloalkanes are cleaved by bromine at -80° with a higher rate for the five-membered ring.

NMR spectroscopy was used for investigating the formation of ate complexes between ethyllithium and the ethyl compounds of three metals of Group IIB. The changes of the methylic triplet and methylenic quadruplet were followed as a function of the initial ratio of the reagents in the solution. It was observed that: (a) ethyllithium and diethylmercury in benzene exchange their ethyl groups very slowly; (b) a fast exchange reaction takes place between ethyllithium and diethylcadmium in benzene, without however, formation of any detectable ate complex; on the addition of a small amount of diethylether (Et 2 O) or tetrahydrofuran (THF), a 1:1 complex, lithium triethylcadmium, is formed which is more stable in the presence of the cyclic ether; (c) a 1.1 complex, (C 2 H 5 ) 3 ZnLi, is formed in pure benzene as well as in a mixed reaction medium: benzene+diethylether or benzene+THF. On the addition of various amounts of ether to a lihiumtriethylzinc solution in benzene, the changes of the ethyl signals demonstrate the existence of the following species: LiEt 3 Zn·Et 2 O, LiEt 3 Zn·(THF) 2 . LiEt 3 Zn-DME. Similarly, the formation of LiEt 3 Cd(THF) 2 by the addition of THF to a benzene solution of EtLi and Et 2 Cd has been investigated.

The galvanostatic method has been applied to the study of the dismutation of organomercury radicals formed by the electrochemical reduction of organomercury salts on the mercury surface. The relative stabilities of organomercury radicals have been found to follow the series AlkHg· >ArHg·, CH2CHHg· ? PhCH2Hg·. The lifetimes on the mercury surface have been determined as 10−2 to 5 x 10−2 sec for AlkHg·, 1 x 10−4 to 2 x 10−4 for ArHg· and CH2CHHg.·, and < 10(su−4) sec for PhCH(in2)- Hg·. The CHg bond in radicals on the mercury surface is more stable than that in radicals generated under homogeneous conditions. This has been attributed to the stabilising effect of the metal.

A study of organomercury compounds is reported. The IR and Raman spectra were measured and frequency assignments are made for 21 compounds. The characteristic frequencies of the -CH 2 HgX and the -CH 2 HgCH 2 -groups were determined and inferences are made on the molecular structure. Normal coordinate analysis was performed for diethylmercury, allylmercury chloride, allylmercury bromide, dibenzylmercury and benzylmercury chloride, bromide and iodide. The force constants in the environment of the Hg atom were refined by the least-squares method. It was found that the force constants of the C-Hg stretching vary in the range from 2.53 to 2.67 mdyn/A.

The reaction of bis(triethylgermyl)mercury with 3,5-di-tert-butyl-l,2benzoquinone has been investigated. It has been shown by means of ESR spectroscopy that the primary reaction step is a one-electron transfer from a germylmercurial compound to quinone, the paramagnetic species observed being o -semiquinone derivatives. The adduct, 3,5-di-tert-butyl-l,2-bis(triethylgermyloxy)benzene, is formed via the recombination of an ion-radical pair in the solvent cage. Partial exit of triethylgermyl radicals from the cage leads to the generation of hexaethyldigermane as one of the reaction products. Under more drastic temperature conditions, the same quinone reacts with diethylmercury via a one-electron transfer stap. The observed ESR spectrum has been attributed to a mercury-containing chelate of 3,5-di-tert-butyl-l,2-benzosemiquinone.

The infra-red spectra of divinylmercury, ethylvinylmercury, diethylmercury, divinylzinc, diethylzinc, diethylcadmium, tetraethyltin, tetravinyltin, triethylphosphine and trivinylphosphine have been examined in the liquid state over the region from 650–3500 cm −1 . For each spectrum many of the vibrational frequencies have been assigned. In the 1100–3000 cm −1 region the vinyl and the ethyl compounds each show a characteristic band pattern which is almost independent of the nature of the metal or metalloid atom bonded to the vinyl or to the ethyl groups.

The pyrolysis of diethylmercury has been studied in a toluene carrier flow System from 601 to 673 °K using total pressures of 1.04 to 7.75 mm. The progress of the reaction was followed by measuring the amounts of unreacted alkyl. Partial solution of butane in the toluene condensed at the outlet of the reactor made full product analysis difficult. Complete analysis in a number of runs did yield a good material balance between alkyl decomposed and [Formula: see text].[Formula: see text][Formula: see text][Formula: see text][Formula: see text]The Arrhenius equation for reaction 1, log k1(s−1) = 15.4 − (45 700 ± 1 000)/2.3 RT, is in excellent agreement with that estimated by Benson and O'Neal. Based on a number of simplifying approximations, log k3(cm3mol−1s−1) = 10.9 − (9 300 ± 2 000)/2.3 RT. The estimated disproportionation to combination ratio, K5/K4 = 0.09 – 0.12 is in good agreement with earlier work.Approximate correction of E1 to absolute zero yields D(C2H5Hg—C2H5) = 43.7 kcal mol−1 and therefore by difference D(Hg—C2H5) = 6.5 kcal mol−1.

The vibrational spectra are presented and interpreted for six compounds containing the CH 3 Hg group; for diethylmercury and ethylmercuric bromide; for dibenzylmercury, benzylmercuric chloride and bromide; and for allylmercuric iodide. A complete normal coordinate calculation is reported for methylmercuric iodide. Characteristic frequencies for the CH 3 Hg group are given for four other compounds. The infra-red spectra are given and assigned for several compounds containing the C 6 H 5 Hg group, and discussed in terms of possible structures for some of them. Spectra are also given for some p -substituted phenylmercuric compounds.

1. When compared with diethylmercury and diethylcadmium, and also with hexamethyldigermane and hexaethyldisilane, a strong bathochromic shift of the absorption maxima is observed in the electronic absorption spectra of the compounds [(C2H5)3Ge]2M (M=Cd, Hg). 2. The bathochromic shift is caused by the participation of the d10 electrons of the Cd and Hg atoms in forming a bond between the metal and germanium.

1. An investigation is described of the reaction of organomercury compounds with stannous salts in an inert solvent, i.e., a solvent which does not contain a mobile hydrogen atom. It was shown that under these conditions no side reaction occurs with formation of (RO)2SnX2, which is formed when acetone or alcohol is used as solvent. 2. Reaction between dipropenylmercury and stannous bromide gave dipropenyltin dibromide, whereas in the corresponding reaction of diisopropenylmercury we isolated diisopropenyltin dibromide, tetraisopropenyltin and isopropenylmercury bromide. 3. The reactions of diphenylmercury, di-p- and di-o-tolylmercurys, di-1-naphthylmercury, and diethylmercury with stannous chloride, and also with stannous bromide in the case of diphenylmercury, gave the normal products.

THE interest in dimethylmercury in connexion with studies of environmental pollution prompts us to report a convenient and comparatively safe method for handling this volatile and extremely toxic compound. We have found that dimethylmercury may be stored, until ready for release, in the form of an inclusion compound, the organometallic guest being accommodated in the relatively large, approximately hour-glass shaped, cavity1,2 formed by the clathrate3 host, 4-p-hydroxyPhenyl-2,2,4-trimethylthiochroman (Structure I). This represents the first successful attempt to prepare a stable inclusion compound containing dimethylmercury, although diethylmercury and longer chain mercury dialkyls have been reported4 to form inclusion compounds with urea; diethylmercury has also been included5 in the tri-o-thymotide chanel structure.

Efficient and selective photoalkylation of 10-methylacridinium ion with tetra-alkyltin compounds and diethylmercury is initiated by electron transfer from the alkylmetals to the singlet excited state of 10-methylacridinium ion in acetonitrile under irradiation with visible light.

A method for the determination of nanogram amounts of dimethyl- and diethylmercury and methyl- and ethylmercury chloride in air has been developed by using gas chromatography interfaced with atomic absorption spectrometry. The mercury species were separated using dual columns connected in parallel. After separation the compounds were cracked in a furnace and the resulting free mercury was passed through the optical cell of an atomic absorption instrument tuned to the mercury resonance line at 253.7 nm. Parameters including the type of column packings, the temperature of the pyrolyser and the optimum gas flow-rate were studied. The detection limits are 0.2 ng of mercury for dimethylmercury and diethylmercury and 0.5 ng of mercury for methylmercury chloride and ethylmercury chloride. Analytical results for air sampled from different sources are presented.

The results of measurements of thermal explosions for mixtures of methyl isocyanide with ethyl isocyanide diethylmercury and di-t-butyl peroxide in spherical vessels near 350 °C are reported. Although the linear mixture rule holds quite well with ethyl isocyanide, it appears to fail mildly for diethylmercury; in the case of di-t-butyl peroxide too much reaction occurs in the inlet to the reaction vessel for a test of the rule to be made. Approximate measurements of the thermal conductivities for ethyl isocyanide and diethylmercury are reported.

THE interest in dimethylmercury in connexion with studies of environmental pollution prompts us to report a convenient and comparatively safe method for handling this volatile and extremely toxic compound. We have found that dimethylmercury may be stored, until ready for release, in the form of an inclusion compound, the organometallic guest being accommodated in the relatively large, approximately hour-glass shaped, cavity1,2 formed by the clathrate3 host, 4-p-hydroxyPhenyl-2,2,4-trimethylthiochroman (Structure I). This represents the first successful attempt to prepare a stable inclusion compound containing dimethylmercury, although diethylmercury and longer chain mercury dialkyls have been reported4 to form inclusion compounds with urea; diethylmercury has also been included5 in the tri-o-thymotide chanel structure.