Two Mercury Chloro Thiocyanate Complexes: NH4[HgCl2(SCN)] and NH4[HgCl(SCN)2]

Single crystals of NH₄[HgCl₂(SCN)] ( 1 ) and NH₄[HgCl(SCN)₂] ( 2 ) are obtained by slow evaporation of ethanol solutions of HgCl₂ and NH₄SCN or Hg(SCN)₂ and NH₄Cl. 1 crystallizes in the monoclinic space group P2₁ (a = 9.297(1), b = 4.171(1), c = 9.198(1)Å, β = 92.827(5)°). The structure consists in HgCl₂(SCN) linear chains, extending along the twofold axis, connected through the ammonium ions. 2 crystallizes in the monoclinic space group C2/c (a = 7.088(1), b = 19.986(2), c = 5.958(1)Å, β = 100.718(5)°). The structure consists of HgCl(SCN)₂ molecules connected through the ammonium ions. The second order non linear optical properties of 1 are discussed.     

Theoretical Study of the Products of Acetylene Addition to HgCl2

The ab initio MP2 method is used with the LANL2DZ basis to calculate the mercury chloride ,-complex with two acetylene molecules (1) and various isomeric forms of mercury di()-vinyl chloride -complexes (2): cis-cis (2A), cis-trans (2B), and trans-trans (2C). The ,-complex is the most stable form of all those considered; the difference between 1 and 2A is 24.9 kcal/mole. A relation between the total energies (kcal/mole) for isomeric forms 2 is established to be 2A (0) < 2B (0.98) < 2C (1.58). Complex 1 is shown to be transformed into 2A via the intermediate formation of 3, which is a hybrid form of the complex (,-complex of mercury chloride with two acetylene molecules). The structures of the transition states for the transformations of 1 into 3 (structure 4) and of 3 into 2A (structure 5) and the corresponding transition activation energies are determined. The interaction of 2A, 2B, and 2C with the Cl^- anion as a model nucleophile is considered. It is shown that the resulting anions (6A, 6B, 6C) have a planar structure with the relative stability increasing in the series 6A<6B<6C.     

Formation of a novel 1D supramolecule [HgCl2(ptz)]2.HgCl2 (ptz = phenothiazine): a new precursor to submicrometer Hg2Cl2 rods

A novel supramolecule [HgCl(2)(ptz)](2).HgCl(2) (ptz = phenothiazine) with uncoordinated inorganic salt HgCl(2) presented in a 1D chain was first prepared and then successfully applied as a new precursor in the preparation of submicrometer Hg(2)Cl(2) rods. Single crystal X-ray analysis showed that the 1D chain structure is stabilized by hydrogen bonds between adjacent chains and the coordination mode of the ligand phenothiazine is unusual with large steric inhibition other than the chain directions. The results revealed that the particular chain structure plays a significant role in the formation of the Hg(2)Cl(2) rods.     

Spectrophotometric determination of the stability constants of HgCl(-)3 and HgCl(2-)4 in aqueous ethanol

The stability constants of HgCl(-)(3) and HgCl(2-)(4) in 60% aqueous ethanol (v/v) were determined by spectroscopy at 25 degrees and constant ionic strength and acidity; beta(1) was 3 +/- 1 and beta(2) 9 +/-3.     

Preparation of 2,2′-octahydrodithienyl and its complexes with HgCl2 and CdCl2

Conclusions The ionic hydrogenation of 2,2-dithienyl with triethylsilane and trifluoroacetic acid gave 2,2-octahydrodithienyl, which was characterized by its complexes with HgCl₂ (II) and CdCl₂ (II).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1173–1174, May, 1976.     

Experimente und Modellrechnungen zum chemischen Transport von WO2 mit HgCl2 oder HgBr2

Experiments and Calculations on the Chemical Transport of WO₂ with HgCl₂ or HgBr₂ Transport experiments with WO₂ or WO₂ + W₁₈O₄₉ or W + WO₂ as starting phases show that HgCl₂ or HgBr₂ are suitable transport agents. When using HgBr₂ we observed (in customary silica ampoules) unusual high transport rates n′ > 1000 mg/h. Experimental and calculated results agree to a large extent if the presence of small amounts of H₂O from the quartz glass wall and the resulting gaseous particles (for example HCl or HBr) formed under equilibrium conditions as well as an influence of convection are taken into consideration.     

ChemInform Abstract: Theoretical Study of the Crystal HgCl2 Compound

ChemInform 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.     

Ab initio MP2 calculations of the products of acetylene addition to HgCl2

Gas-phase reaction of acetylene with HgCl₂ resulting in -chlorovinylmercury derivatives and their interaction with Cl^– and I^– anions and KI molecule was studied by the ab initio MP2 method with the Dunning—Hay double zeta basis set and LanL pseudopotential for Hg, K, and I atoms. The reaction was shown to proceed via a -complex of acetylene and HgCl₂ (the calculated enthalpy of formation is –6.5 kcal mol^–1). According to calculations, the activation energy of formation of cis--chlorovinylmercury chloride from acetylene and HgCl₂ is 31 kcal mol^–1. Chloride and iodide anions and KI molecule are readily added to both cis- and trans-isomer of -chlorovinylmercury chloride to give stable species.     

Hydrothermal synthesis, crystal structure and photoluminescence of [HgCl2(C6NO2H5)]nn[HgCl2]n(C6NO2H5)

The first example of isonicotinic acid compounds with infinite mercury halide chains, [HgCl₂(C₆NO₂H₅)]_n n[HgCl2]n(C₆NO₂H₅) (1), was synthesized through hydrothermal reactions and structurally characterized by X-ray single crystal diffraction. Compound 1 features a one-dimensional (1-D) motif, based on infinite 1-D [HgCl₂(C₆NO₂H₅)]_n chains, neutral HgCl₂ moieties and isolated isonicotinic acid molecules. The [HgCl₂(C₆NO₂H₅)]_n chains, HgCl₂ moieties and isonicotinic acid molecules are interlinked by hydrogen bonds and π-π interactions to give a two-dimensional supramolecular layer. Photoluminescent investigation reveals that the title compound exhibits a strong emission in blue region. The emission band is identified as the π -π* transitions of the isonicotinic acid moieties.     

Theoretical study of the solvation of HgCl2, HgClOH, Hg(OH)2 and HgCl3(-): a density functional theory cluster approach

The determination of the solvation shell of Hg(II)-containing molecules and especially the interaction between Hg(II) and water molecules is the first requirement to understand the transmembrane passage of Hg into the cell. We report a systematic DFT study by stepwise solvation of HgCl(2) including up to 24 water molecules. In order to include pH and salinity effects, the solvation patterns of HgClOH, Hg(OH)(2) and HgCl(3)(-) were also studied using 24 water molecules. In all cases the hydrogen bond network is crucial to allow orbital-driven interactions between Hg(II) and the water molecules. DFT Born-Oppenheimer molecular dynamics simulations starting from the stable HgCl(2)-(H(2)O)(24) structure revealed that an HgCl(2)-(H(2)O)(3) trigonal bipyramid effective solute appears and then the remaining 21 water molecules build a complete first solvation shell, in the form of a water-clathrate. In the HgCl(2), HgClOH, Hg(OH)(2)-(H(2)O)(24) optimized structures Hg also directly interacts with 3 water molecules from an orbital point of view (three Hg-O donor-acceptor type bonds). All the other interactions are through hydrogen bonding. The cluster-derived solvation energies of HgCl(2), HgClOH and Hg(OH)(2) are estimated to be -34.4, -40.1 and -47.2 kcal mol(-1), respectively.     

Catalytic HgCl2—Samarium System Induced Reductive Coupling of Nitriles with Nitro Compounds

The intermolecular coupling of a nitro group with a cyano group mediated by a Sm(Hg) amalgam prepared from metal samarium powder and catalytic mercury dichloride was studied.     

Na-nitroprusside and HgCl2 modify the water permeability and volume of human erythrocytes

The passage of water through the aquaporin-1 (AQP1) transmembrane channel protein of the human erythrocyte is known to be inhibited by organic mercurials such as p-chloromercuribenzoate (pCMB), which react with the free SH-group of the critical cysteine (Cys189) located near the constriction of the AQP1 water-specific channel. Sodium nitroprusside (SNP), which is known as a nitric oxide (NO) donor in interactions with SH-containing molecules, is shown here to suppress the diffusional water permeability (P(d)) of the erythrocyte membrane, presumably as a result of reaction with the Cys189 of the human erythrocyte AQP1 water channels. Further, treatment of erythrocytes with HgCl(2) is found to result in a cell volume decrease that can be related to activation of membrane K(+)-selective Gárdos channels and subsequent loss of intracellular K(+) and cell shrinkage. The variations in P(d) and volume of the erythrocyte were deduced from induced variations in the measured proton ((1)H) nuclear magnetic resonance (NMR) transverse (T(2)) relaxation functions of water exchanging between diamagnetic intracellular and paramagnetic extracellular compartments of the 20-25% hematocrit samples. The extracellular solvent contained 10 mM membrane-impermeable paramagnetic Mn(2+) ions. The (1)H-T(2) NMR technique allows determination of the time constant tau(exch) (for exchange of the erythrocyte intracellular water) that is inversely proportional to the permeability coefficient P(d) when the intracellular water volume is left unmodified, as in the case of SNP-treated erythrocytes. However, for HgCl(2)-treated erythrocytes, this technique showed simultaneous variation of both tau(exch) and the volume ratio V(in)/V(out) of intracellular and extracellular water in proportions suggesting that P(d) was left unmodified. The HgCl(2) effect has been found to be partly reversible by the reducing activity of added mercaptoethanol.     

HgCl2(Caf): Co‐crystallization of Mercuric Chloride and Caffeine

Colourless single crystals of the co‐crystallizate of mercuric chloride and caffeine, HgCl₂(Caf), were obtained from an ethanolic solution of mercuric chloride, HgCl₂, and caffeine (Caf) and recrystallized from hot water. The crystal structure (monoclinic, P2₁, Z = 2, a = 398.36(8), b = 1964.5(4), c = 809.6(2) pm, β = 99.24(3)°, Z = 2, R₁ = 0.0584 for 1430 F_o > 4σ(F_o)) contains helical chains (parallel to the 2₁ screw axis) of almost unaffected HgCl₂ molecules and caffeine molecules which are very weakly bound to one keto‐oxygen atom (O4) of one and N9 of a second caffeine molecule at distances of 282 and 281 pm, respectively. To the contrary, theoretical calculations show that the molecule HgCl₂(Caf)₂ is stable (in the gas phase at T = 0 K) with surprisingly strong bonding as indicated by the “tetrahedrization” of the molecule.     

A Convenient Method for Reductive Desulfonylation of β-Ketosulfones with Sm/HgCl2 System

The Sm/HgCl₂ system reduces β-ketosulfones to the corresponding ketones in moderate to good yield under mild conditions.     

Investigation of mercury metallothionein complexes in tissues of rat after oral intake of HgCl2

Mercury, a highly toxic metal found widely throughout the environment, is a potent inducer of metallothionein (MT) expression. The role of MTs in the detoxification of mercury after its oral intake in mammals is studied. After feeding rats with mercuric chloride by gastric gavage, the distribution of heavy metals in rat tissues was investigated by inductively coupled plasma mass spectrometry (ICP‐MS). Extensive accumulation of mercury, copper and zinc in kidney and liver is observed. A homemade preparative size‐exclusion chromatography (SEC) column (30 cm × 1.9 cm) packed with Sephadex G‐75 (40–120 µm particle size) gel (Pharmacia) was used for the purification of MT fractions in rat tissues. Preliminary results from SEC indicate that the mercury‐binding MT levels in liver were much lower than in kidney. The MT fractions were collected, desalted, and then separated by reversed‐phase high‐performance liquid chromatography (HPLC) with UV–Vis spectrometry, ICP‐MS and electrospray ionization MS detection. One major and several minor peaks were observed in the HPLC chromatograms of the MT fraction for the kidney sample. UV absorption spectra indicate that MTs were found to bind with mercury. There were no significant mercury‐binding MTs detected in the liver sample using UV detection. ICP‐MS detection showed that mercury‐binding MTs in kidney contained large amounts of mercury and copper but little zinc. Further characterization with ESI‐MS showed that the major peak found in kidney contained Hg₆Cu, Hg₅Cu₂‐MT‐2c and Hg₆‐MT‐2β, Hg₆Cu‐MT‐1γ, Hg₇‐MT‐2α. However, distinction between copper and zinc could not be made based on current mass spectrometric analysis because of instrumental resolution limitations. Copyright © 2005 John Wiley & Sons, Ltd.     

[{Er(NC5H4COOH)(H2O)2}2(H5O2)(HgCl5)(HgCl4)2(H2O)2]n – Synthesis,Crystal Structure and Properties

The first heterometallic 4f‐5d inorganic‐organic metal‐isonicotinic acid hybrid [{Er(NC₅H₄COOH)(H₂O)₂}₂(H₅O₂)(HgCl₅)(HgCl₄)₂(H₂O)₂]_n ( 1 ) has been synthesized via hydrothermal reaction and structurally characterized. Complex 1 crystallizes in the space group C2/c of the monoclinic system with four formula units per unit cell: a = 24.194(3), b = 20.792(3), c = 15.289(4) Å, β = 128.39(2)°, V = 6028(2) ų, C₃₆H₄₇Cl₁₃Er₂Hg₃N₆O₂₀, M_r = 2280.94, D_c = 2.513 g/cm³, S = 0.929, μ(MoKα) = 11.017 mm^?1, F(000) = 4248, R = 0.0425 and wR = 0.0739. The crystal structure analysis reveals that the title complex is characteristic of a one‐dimensional chain‐like structure. Photoluminescent investigation reveals that the title complex displays interesting emissions. Optical absorption spectra of 1 reveal the presence of an optical gap of 3.45 eV. The magnetic properties show that complex 1 exhibits antiferromagnetic interactions.