Mercurous Chloride Research Articles

Pressure induced structural phase transitions of technologically significant mercurous chloride at room temperature: An account from first-principle DFT and Born–Oppenheimer molecular dynamics studies

This paper reports for the first time an in-depth study based on first-principle calculations to unveil the underlying physics that governs the pressure induced structural phase transitions of Hg2Cl2 compound at room temperature. The phonon dispersion relations and phonon density of states have been critically explored for the tetragonal and orthorhombic phases of the compound to unveil the phonon modes associated with the phase transitions. The nature of the phase transition whether it is “displacive” or of “order–disorder” type has also been explored. We believe that the present study based on density functional theory and Born–Oppenheimer molecular dynamics calculations will help understand the underlying physics behind the above referred phase transitions and the anisotropic behavior of the compound, which in turn bears technologically significant relevance for its applications in optoelectronic devices, acousto-optic tunable filters, and in fiber-optic communication systems.

Structural and electronic properties of wide band gap charge transfer insulator Hg2Cl2: Insights from the first-principle calculations

The structural and electronic properties of Mercurous Chloride (Hg2Cl2) in its tetragonal (I4/mmm) phase at room temperature have been investigated from the first principle calculations. Detail calculations within the framework of density functional theory (DFT) upon incorporation of spin-orbit coupling (SOC) reveal that Hg2Cl2 is a wide band gap charge transfer (CT) insulator with band gap energy (Eg) ∼ 3.96 eV. Despite being a CT insulator, the orbital resolved PDOS of Hg2Cl2 compound exhibit energy dispositions that do not obey the Zaanen – Sawatzky – Allen (ZSA) diagram. The effect of on-site Coulomb repulsion (Hubbard +Udd) on the band gap of the compound has also been studied in detail. The Mulliken bond population, electronic charge density distribution and Bader charges analyses have been explored to unveil the covalent and ionic interactions between Hg and Cl atoms of the Hg2Cl2 compound. The Natural Bond Orbital (NBO) analyses have been performed to gain deeper insights on the CT interactions between Hg and Cl atoms of Hg2Cl2. The rationale behind the distortions of the octahedral domains within Hg2Cl2 crystal has also been elucidated in detail.

Quasi-collinear IR AOTF based on mercurous halide single crystals for spatio-spectral hyperspectral imaging.

The paper aims to show the advantages of the infrared-optimised quasi-collinear AOTF (acousto-optic tunable filter) for the spatio-spectral hyperspectral imaging system. The optimisation process is presented based on the selected tetragonal anisotropic materials with exceptional optical and acousto-optical properties in IR (infrared) spectral region. These materials are further compared in terms of their features and suitability for AOTF design. The spectral resolution is considered as the main optimising parameter. Resulting from the analysis, the mercurous chloride (Hg2Cl2) single crystal is selected as a representative of the mercurous halide family for the presentation of the quasi-collinear AOTF model operating in LWIR (long-wave infrared) spectral band. The overall parameters of the AOTF model such as spectral resolution, chromatic field of view, acoustic frequency, and operational power requirements are estimated and discussed in results.

A test strip platform based on a whole-cell microbial biosensor for simultaneous on-site detection of total inorganic mercury pollutants in cosmetics without the need for predigestion

Mercury pollutants such as mercuric chloride (HgCl2), mercurous chloride (Hg2Cl2) and mercuric ammonium chloride (Hg(NH2)Cl) are often found in cosmetics. Previous attempts at the on-site detection of mercury were hindered by the complicated and dangerous pretreatment procedure of converting various forms of mercury to Hg (II) ions. In this study, a test strip platform was developed based on a whole-cell microbial biosensor for the simultaneous detection of soluble and insoluble inorganic mercury pollutants in cosmetics without the need for predigestion. The genetic circuits with constitutively expressed MerR as sensor proteins and inducible red fluorescent protein (RFP) as the reporter were introduced into Escherichia coli to construct the mercury detection biosensor. The RFP fluorescence intensity of this biosensor showed a excellent linear relationship (R2=0.9848) with the Hg (II) concentration ranging from 50nM to 10μM in Luria-Bertani (LB) broth. Further research indicated that this biosensor could respond not only to Hg (II) ions but also to insoluble Hg2Cl2 and Hg2Cl2. The transcriptomic results confirmed the mercury conversion ability of the whole-cell biosensor from a gene expression perspective. This biosensor was embedded on filter paper to form a test strip, which could be used to determine whether the total inorganic mercury pollutants in cosmetics exceeded 1mg/kg. Therefore, this strip provided a low cost, easy-to-use, and instrument-independent method for the detection of mercury pollution in cosmetics, while this study revealed the unique advantages of microbial biosensors in the automatic bioconversion of targets.

Study on Pure Mercurous Chloride Leaching with Sodium Thiosulfate

Mercurous chloride (Hg2Cl2), also known as Calomel, is a typical mercury-containing mineral found in nature. In this work, the leaching behaviour of pure mercurous chloride dissolved in pure water and in thiosulfate solution was investigated. The mercurous chloride hardly dissolved in sulfuric acid solution at pH of 3 and pure water at pH of 6.4, with the corresponding maximum Hg extraction percentage at 3.1 and 7.5% respectively. However, the Hg extraction percentage increased to 45.8% in sodium hydroxide solution at pH of 11.2. The mercury extraction percentage reached a high of 62.6% in thiosulfate solution, and the leaching kinetics results show that the activation energy is 6.6 kJ/mol. This study indicates that the thiosulfate solution can efficiently extract mercury from mercurous chloride.

Regenerating mercurous chloride-loaded porous carbon complex through steam-induced thermal activation

In the present study, the spent mercurous chloride catalyst (coal carbon base) used in the PVC production process was regenerated to separate the Mercury to recover the porous carbon for possible reuse in other applications. The effect on regeneration temperature and the regeneration duration was assessed on the Mercury removal capacity using various physicochemical characterization techniques, such as FT-IR, XPS, SEM, BET, and Raman spectroscopy. The optimal regeneration conditions were determined to enhance the yield and the methylene blue number. The optimal conditions were found to be a temperature of 900 °C and an activation duration of 1.5 h. All the regeneration experiments were conducted at a nitrogen flow of 100 L h−1 and water vapor flow of 30 L h−1. The methylene blue adsorption capacity of the regenerated carbon was found to be 173 mg g−1, with near 99% recovery of mercury and with the yield of carbon being 88.42%. The work proves that both mercury removal and carbon regeneration can be significantly improved by purging the system with a nitrogen-water vapor flow at the optimal condition.

Mercury Toxicity and Contamination of Households from the Use of Skin Creams Adulterated with Mercurous Chloride (Calomel).

Inorganic mercury, in the form of mercurous chloride, or calomel, is intentionally added to some cosmetic products sold through informal channels in Mexico and the US for skin lightening and acne treatment. These products have led to multiple cases of mercury poisoning but few investigations have addressed the contamination of cream users’ homes. We report on several cases of mercury poisoning among three Mexican-American families in California from use of mercury-containing skin creams. Each case resulted in widespread household contamination and secondary contamination of family members. Urine mercury levels in cream users ranged from 37 to 482 µg/g creatinine and in non-users from non-detectable to 107 µg/g creatinine. Air concentrations of up to 8 µg/m3 of mercury within homes exceeded the USEPA/ATSDR health-based guidance and action level of <1.0 μg/m3. Mercury contamination of cream users’ homes presented a multi-pathway exposure environment to residents. Homes required extensive decontamination, including disposal of most household items, to achieve acceptable air levels. The acceptable air levels used were not designed to consider multi-pathway exposure scenarios. These findings support that the calomel is able to change valence form to elemental mercury and volatilize once exposed to the skin or surfaces in the indoor environment.

OFT sectorization approach to analysis of optical scattering in mercurous chloride single crystals

This paper is devoted to the application of the optical Fourier transform (OFT) for the study and evaluation of optical scattering in the latest generation of calomel single crystals ready for application in several possible devices such as IR polarizers and acoustooptic tunable filters (AOTF). There are numerous effects that are responsible for the scattering of optical wave passing through the crystal sample volume and surface layers because they affect the optical crystal quality. The scattering level is a crucial and limiting parameter in many technical applications of the evaluated crystal. The proposed approach is based upon the high dynamic range optical FT configuration, creating the amplitude spectrum in the focal plane and its spatial angular distribution analysis based on the spectrum sectorization. The optical scattering pattern was tested in nine locations within each crystal sample volume and on numerous crystal samples. The experimental results are presented and discussed.

The Properties of Protease Isolated from Tissues of Benign and Malignant Kidney Tumors Patients

The research includes the study of some protease properties in seven patients diagnosed with kidney tumors. Three of them were benign and the others were malignant. The samples were collected from the patients directly after undergoing the surgery in Al-Jamhoory hospital in Nineveh Governorate, Iraq. Protease enzyme was isolated using different biochemical techniques, like ammonium sulphate precipitation, dialysis and gel filtration chromatography on sephadex G-100. The comparative molecular weight of protease was determined using gel filtration and was found to be (72000 and 75000 ± 2000) dalton for benign and malignant tumors respectively. The results showed that there was a (55%) increase in the specific activity of protease in malignant kidney tumors than benign. The optimum conditions for protease activity were obtained using sodium borate buffer at pH (8.8) for (1) minute incubation at (40°C) and (0.4) mM of casein as a substrate Vmax and Km were found to be (0.87 U/ml) and (0.22 mM) respectively by Linweaver-Burk plot. Finally, the effect of some chemical compounds like iodoacetamide, mercurous chloride, zinc sulphate showed an inhibition impact on protease activity while calcium sulphate and magnesium chloride demonstrated an increase effect on the protease activity.

Biosequestration, Transformation, and Volatilization of Mercury by Lysinibacillus fusiformis Isolated from Industrial Effluent

In the present study, an efficient mercury-tolerant bacterial strain (RS-5) was isolated from heavy-metalcontaminated industrial effluent. Under shake flask conditions, 97% of the supplemented mercuric chloride was sequestered by the biomass of RS-5 grown in a tryptone soy broth. The sequestered mercuric ions were transformed inside the bacterial cells, as an XRD analysis of the biomass confirmed the formation of mercurous chloride, which is only feasible following the reaction of the elemental mercury and the residual mercuric chloride present within the cells. Besides the sequestration and intracellular transformation, a significant fraction of the mercury (63%) was also volatilized. The 16S rRNA gene sequence of RS-5 revealed its phylogenetic relationship with the family Bacillaceae, and a 98% homology with Lysinibacillus fusiformis, a Gram-positive bacterium with swollen sporangia. This is the first observation of the sequestration and volatilization of mercuric ions by Lysinibacillus sp.

JEBCAM: Rebirth Brings New Life to an Old Journal and Scientific Scrutiny to the Field

Beginning with the dawn of human consciousness, disease and death have perplexed mankind and resulted in a variety of mystical, religious, and mythological explanations. Stories such as ‘‘Pandora’s box’’ helped provide a reason for disease and other human afflictions. As human societies appeared, certain individuals claimed to be endowed with a special knowledge concerning disease and death, and such personages are evident in early writings from communities in Asia, Africa, and Europe and in the oral traditions of other groups. With advancing civilization, knowledge concerning disease and death became codified and treatises were developed, such as the various papyri attributed to Imhotep in Egypt, the Corpus Hippocraticum from ancient Greece, the writings of Galen of Pergamon in Imperial Rome, the alQ an un fi’l-tibb (Canon of Medicine) by the Central Asian Islamic physician Ab u ‘Al i al-Husayn ibn ‘Abd All ah ibn S in a (also known as Ibn S in a or Avicenna), the Nei Ching Su Wen attributed to the Chinese Yellow Emperor Huang Ti, and the Hindu texts Atharvaveda, Caraka Samhita, and Sushruta Samhita. Over centuries, various adherents came to view these writings as hallowed texts. Although scientific inquiry provided stuttering advances in a variety of disciplines such as mathematics, chemistry, and physics (particularly after the European Renaissance), medicine tended to adhere to the ancient wisdom of these sacred teachings. For example, even though the Dutch scientist Antonie van Leeuwenhoek could see microorganisms with his microscope as early as the 1600s, the germ theory of disease did not reach ascendency until the late 1800s. Until science finally insinuated its way into medical thought in the 19th century, more harm than good generally resulted from care by the supposed healers. Even during the American Civil War (1861-1865), the accepted medical therapy for injuries and illness that could not be treated by amputation was either bloodletting or administration of calomel (mercurous chloride) purgatives, and not unexpectedly most patients receiving such treatments did not survive. Although by the 1800s university-trained physicians in Europe and America could finally begin to categorize and diagnose diseases based on some scientific understanding, the results of their treatments were generally no better than that of any other healing discipline. In fact, the famous 1891 painting The Doctor by Sir Luke Fildes depicted the ‘‘physician in our time’’ who could offer no effective therapy but instead could only sit in vigil until the child either miraculously recovered or died (Figure 1). Thus, from the early-1800s until the mid-1900s (through World War II), there was an explosion of health care theories and disciplines, many offering treatments that were less gruesome and equally effective (or ineffective) as compared with those advocated by the universitytrained medical establishment. Unfortunately, this was also a period of exponential growth for charlatanism and quackery. Even following reforms to medical education as a result of the famous 1910 Flexner report, there were still few successful treatment options for most diseases. Interestingly, despite the relatively poor therapeutic options, death rates had actually fallen and longevity had increased, presumably in part due to improvements in public health as a result of better understanding of infectious disease. Astonishing breakthroughs during the heady half-century from the 1930s to the 1980s brought medical science to the forefront, and the public came to believe that all disease was finally conquerable and that the modern medical therapies dispensed by physicians were ‘‘magic bullets.’’ This period saw the introduction of effective antibiotics, which led the Surgeon General William Stewart to tell the US Congress in 1969 that it was time to ‘‘close the book on infectious diseases. The war against pestilence is over.’’ Medications to treat mental illness obviated the need for asylums and associated barbaric procedures such as shackling, shock therapy, and frontal lobotomy. Surgical procedures became safer and more routine, including open heart surgery and organ transplantation of kidneys, heart, and liver. Vaccinations were developed that basically eliminated the threat of childhood scourges such as poliomyelitis, measles, and mumps. Women who would otherwise have been childless could be made fertile with drugs or

ChemInform Abstract: Inorganic Chemistry and Drug Design

Publisher Summary This chapter discusses some of the current uses of inorganic compounds as drugs and diagnostic agents. It focuses on areas of demonstrated medical and clinical interest. The illustrative examples chosen are mostly concerned with metals and do not form a comprehensive list. The use of inorganic compounds in medicine dates back to ancient times. The wider use of inorganic compounds in health care depends heavily on overcoming the toxicity problem. Arsenic, for example, is widely perceived to be a toxic element, but the enormous variation in toxicity among the types of arsenic compounds is not widely acknowledged: As(III) compounds are usually much more toxic than As(V) compounds, and arsenobetaine (Me 3 As + CH 2 C0 2 − )is relatively nontoxic, which is fortunate because man consumes it regularly in certain fish and crustacea. The Egyptians are said to have used copper to sterilize water in 3000 BC, and the Chinese were using gold in medicine in 2500 BC; mercurous chloride was known to be a diuretic during the Renaissance period, and mercurial diuretics were widely used up until the 1950s.

W3Cl10(Hg2Cl2)2, A Reactive One-Dimensional Polymer of Triangular Tritungsten Clusters with Terminal and Intercluster-Bridging Mercurous Chloride Ligands: Main Group Metal Halide By-Products as Versatile Ligands in Reductive Synthesis of Early Transition Metal Halide Clusters

Solid-state reduction of WCl6 with Hg followed by incomplete sublimation of mercury chlorides generated the tritungsten decachloride—mercury chloride adducts W3Cl10(Hg2Cl2)2−x(HgCl2)x. Thermal equilibration of the solid-state products followed by sublimation of HgCl2 afforded single crystals that include the mercurous chloride adduct W3Cl10(Hg2Cl2)2. Single-crystal diffractometry revealed a one-dimensional polymer of tritungsten decachloride triangular clusters with novel terminal and inter-cluster-bridging ClHgHgCl ligands. The W3 cluster core has similar metrics to that of the benzyltriethylammonium salt of W3(μ3-Cl)(μ-Cl)3Cl9 3−. W3Cl10(Hg2Cl2)2 is the first reported adduct of the binary tungsten chloride W3Cl10. The ClHgHgCl ligands are more labile that the terminal chlorine atoms of W3(μ3-Cl)(μ-Cl)3Cl9 3−. These results demonstrate diverse roles and potential utility of main group element halide by-product ligands in solid-state reductions of transition metal halides.

Effects of impurity (N2) on thermo-solutal convection during the physical vapor transport processes of mercurous chloride

For Ar=5, Pr=1.18, Le=0.15, Pe=2.89, Cv=1.06, <TEX>$P_B$</TEX>=20 Torr, the effects of impurity <TEX>$(N_2)$</TEX> on thermally and solutally buoyancy-driven convection (<TEX>$Gr_t=3.46{\times}10^4$</TEX> and <TEX>$Gr_s=6.02{\times}10^5$</TEX>, respectively) are theoretically investigated for further understanding and insight into an essence of thermo-solutal convection occurring in the vapor phase during the physical vapor transport. For <TEX>$10K{\leq}{\Delta}T{\leq}50K$</TEX>, the crystal growth rates are intimately related and linearly proportional to a temperature difference between the source and crystal region which is a driving force for thermally buoyancy-driven convection. Moreover, both the dimensionless Peclet number (Pe) and dimensional maximum velocity magnitudes are directly and linearly proportional to <TEX>${\Delta}T$</TEX>. The growth rate is second order-exponentially decayed for <TEX>$2{\leq}Ar{\leq}5$</TEX>. This is related to a finding that the effects of side walls tend to stabilize the thermo-solutal convection in the growth reactor. Finally, the growth rate is found to be first order exponentially decayed for <TEX>$10{\leq}P_B{\leq}200$</TEX> Torr.

Investigation of a Mercury Speciation Technique for Flue Gas Desulfurization Materials

Most of the synthetic gypsum generated from wet flue gas desulfurization (FGD) scrubbers is currently being used for wallboard production. Because oxidized mercury is readily captured by the wet FGD scrubber, and coal-fired power plants equipped with wet scrubbers desire to benefit from the partial mercury control that these systems provide, some mercury is likely to be bound in with the FGD gypsum and wallboard. In this study, the feasibility of identifying mercury species in the FGD gypsum and wallboard samples was investigated using a large sample size thermal desorption method. Potential candidates of pure mercury standards including mercuric chloride (HgCl2), mercurous chloride (Hg2Cl2), mercury oxide (HgO), mercury sulfide (HgS), and mercuric sulfate (HgSO4) were analyzed to compare their results with those obtained from FGD gypsum and dry wallboard samples. Although any of the thermal evolutionary curves obtained from these pure mercury standards did not exactly match with those of the FGD gypsum and wallboard samples, it was identified that Hg2Cl2 and HgCl2 could be candidates. An additional chlorine analysis from the gypsum and wallboard samples indicated that the chlorine concentrations were approximately 2 orders of magnitude higher than the mercury concentrations, suggesting possible chlorine association with mercury.

New 3D radiochromic gel dosimeters with inhibited diffusion

Two new radiochromic gels for 3D dosimetry, both with inhibited diffusion, are described. The first dosimeter is based on the radiation-induced creation of a dye Turnbull blue. The dose sensitivity of the gel measured in terms of spectrophotometric absorbance is (5.0 ± 0.1)×10−3 Gy−1cm−1 (1σ) and the background value 24 h after gel preparation is 0.14 cm−1. The diffusion coefficient of the gel stored at 24°C is less than 4x10−3 mm2h−1 (1σ). The second dosimeter makes use of the radiation-induced formation of insoluble mercurous chloride which creates a fog inside an originally bright gel. The dose sensitivity of the dosimeter is (3.8 ± 0.2)x10−2 Gy−1cm−1 (1σ) and its background value 24 h after preparation is 0.18 cm−1. The diffusion coefficient is less than 2x10−4 mm2h−1 (1σ).

Investigation of a mercurous chloride acousto-optic cell based on longitudinal acoustic mode

A number of spectral imagers using acousto-optic tunable filters (AOTFs) operating from the UV to the longwave infrared (LWIR) using KDP, MgF(2), TeO(2), and Tl(3)AsSe(3) crystals to cover different spectral regions have been developed. In the LWIR there is a lack of high quality acousto-optic (AO) materials. Mercurous halide (Hg(2)Cl(2) and Hg(2)Br(2)) crystals are highly anisotropic with a high AO figure of merit due to slow acoustic velocities and high photoelastic constants and are transparent over a wide spectral region from 0.35 to 20 mum for Hg(2)Cl(2) and from 0.4 to 30 mum for Hg(2)Br(2). AO modulators, deflectors, and AOTFs based on these crystals can operate over a wide spectral range. Single crystals of these materials are being grown and some prototype devices have been fabricated. Results are presented from device characterization for an AO cell fabricated in Hg(2)Cl(2) based on longitudinal acoustic mode propagation. This device was very useful in demonstrating the AO interaction as well as soundness of the transducer bonding technique. Acoustic phase velocity is calculated and measured, diffraction efficiency is obtained from experiments, and the AO figure of merit of the sample is evaluated.

HYPERTENSIVE ENCEPHALOPATHY INDUCED BY MERCURY POISONING; A REPORT OF 3 CASES (IN AN IRANIAN FAMILY)

Objective Mercury poisoning is one of the important recent causes of mortality and mortality in children worldwide, particularly in industrial environments; mercury is a poisonous metal, especially harmful to the nervous and immune systems and the kidneys and can even be fatal. Elemental mercury is present in thermometers, barometer batteries, sphygmomanometers and latex paints. Inorganic mercury salts are found in antiseptics, pesticides, pigments and explosives and are used as preservatives in medicine. Mercury was once used to stop fever, and this worked because the immune system was so weakened that it could no longer sustain the attack for which the fever was created. Some medical drugs still contain mercury chloride and mercurous chloride and certain forms of mercury are still used in some laxatives. Mercury toxicity of the nervous system causes anorexia, ataxia, lack of ability to coordinate voluntary muscle movements, dementia, depression, dizziness, emotional instability, erethism (abnormal irritability in response to stimulation), incoordination, insomnia, irritability, loss of ability to speak, memory impairment, numbness, saresthesias (sensation of prickling, tingling or creeping on the skin), psychosis, tremors, drowsiness, fatigue and weakness. Other organ damages include kidney failure, headaches, hearing impairment, visual impairment, hypertension, dermatitis, digestive tract problems, colitis, diarrhea, stomatitis and excessive salivation, loss of teeth, metallic taste, chromosomal damage, birth defects and ensuing organ failure. Chronic mercury poisoning can cause Acrodynia (Pink disease). Mercury poisoning is a rare cause of hypertension in children. Herein we report 3 cases, the first a child with hypertensive encephalopathy due to severe mercury poisoning and his two siblings with moderate symptoms. Case report A 10 year old boy was admitted in psychiatric ward of Imam Hossein Hospital with behavioral disorder, irritability, mood change and convulsion. Because of his blood pressure which was 160/120 he was referred and admitted to the Pediatric Nephrology department. On arrival, for his hypotonia and the pink discoloration of his fingers a diagnosis of Acrodynia (Pink disease) was considered; his history showed that he has played with a ball of mercury, taken from a laboratory. He and his 2 siblings received British Anti Lewisite(BAL) and D-penicillamin; at follow-up all symptoms had gradually disappeared and they are well now. Keywords: Mercury poisoning, Children, Renal complications, Hypertensive encephalopathy

Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes

AbstractMercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β‐aminoalkynes in good yields.