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A method is reported for determining selenium (Se) in animal tissue through Schoniger combustion, Se reduction to H2Se, and measurement by flame atomic absorption. The method provides several improvements over present hydrogen selenide generation apparatus and procedure. For the National Bureau of Standards Bovine Liver reference material containing 1.1±0.1 ppm Se, recovery averaged 100% with a relative standard deviation of 15 %. The minimum detecable quantity is 0.04 Ng Se. Data from the literature and results of analyses in our laboratory indicate that the method is adequately sensitive for tissue samples of almost any origin. Overall, our method is sensitive, precise, accurate, and simple and fast enough to use economically in routine monitoring of wildlife samples.

The synthesis of a new chelating reagent, l,l,l-trifluoro-4-(2-thienyl)-4-seleno-3-buten-2-one (SeTTA) by the reaction of hydrogen selenide in a stream of nitrogen gas with TTA in absolute ethanol in the presence of hydrogen chloride is described. The analytical application of SeTTA is also discussed.

Germyl-phosphine and -arsine both react with hydrogen selenide to form digermyl selenide. Evidence is provided by 1H n.m.r. spectroscopy that germyl hydrogen selenide is a reaction intermediate and that germylenebis-(germyl selenide), (GeH3Se)2GeH2, and possibly germylidynetris- and germanetetrayltetrakis-(germyl selenide), (GeH3Se)3GeH and (GeH3Se)4Ge are condensation products. The vibrational spectrum of digermyl selenide is discussed.

Values of the band origins for the near‐infrared rotation—vibration bands v1+v2, v2+v3, 2v1+v3, v1+2v3, 3v1, and 3v1+v3 of H280Se were determined directly from their respective PPJ (J) and RRJ (J) lines. A vibrational analysis of the band origins of these six bands, of four previously analyzed combination bands, and of the three fundamentals led to values for the zero‐order frequencies, anharmonic constants, and the interaction matrix element for a second‐order resonance between levels of the type (v1, v2, v3) and (v1−2, v2, v3+2). Values for the isotopic band center separations Δv0≡v0 (H280Se) —v0 (H2iSe) and for ΔC0≡80C0−iC 0, where i=82, 78, 77, and 76, were obtained from the observed isotopic separations of the PPJ (J) and RRJ (J) lines for several bands. These empirical values of Δv0 are compared with a set of theoretical values calculated using Krimm's approximate isotopic frequency rule and the vibrational constants for H280Se. Values of iA0, iB0, and iC0 were calculated by combining our values of ...

Hydrogen selenide may be generated by the reaction of hydrogen gas with liquid selenium according to the reaction[Formula: see text]where[Formula: see text]The equilibrium constant K of this reaction was measured by passing hydrogen over liquid selenium at controlled rates of flow over the temperature range 525–625 °C. The equilibrium ratio of hydrogen to hydrogen selenide was determined by gas analysis. Over the temperature range 525–625 °C, the equilibrium constant can be expressed by the equation[Formula: see text]This expression leads to ΔH298° = 9 174 ± 107 cal mole−1, ΔF298° = 5 132 cal mole−1, and ΔS298° = 13.56 e.u. (entropy units) for the respective heat, free energy, and entropy of formation of hydrogen selenide from hydrogen and crystalline selenium.

A new procedure for a rapid determination of selenium has been devised by the present authors. Tin(II)-strong phosphoric acid, previously prepared by the authors, has a remarkable decomposing and reducing power, and selenium in various forms can be reduced to hydrogen selenide which is evolved as a gas from samples. Sulfur in various forms is reduced to hydrogen sulfide at the same time. Solid samples such as pyrite can be allowed to decompose rapidly by simple heating with the reagent in an atmosphere of hydrogen. The gas evolved is introduced into an absorbing solution of 5 N sodium hydroxide. Then, a small volume of 30% hydrogen peroxide solution is added. Thus sodium selenate and sodium sulfate are formed in the solution. After adding an excess of concentrated hydrochloric acid and boiling for about twenty minutes with a reflux condenser, the selenic acid is reduced to selenious acid, while the sulfuric acid remains unchanged. The solution is kept at 45°C for several minutes, and solutions of gum arab...

The gravimetric determination of metals as selenides is proposed. Owing to the rapid atmospheric oxidation of sodium selenide and the toxic nature of hydrogen selenide, special apparatus is required. The methods are analogous to precipitation of sulphides. Arsenic, tin, antimony, platinum, ruthenium, palladium, rhodium, rhenium, mercury, silver and gold can be determined. The thermolysis of precipitates formed with arsenic, antimony, mercury, silver, rhenium, platinum, ruthenium, palladium and rhodium has been studied.

The equilibrium constants for hydrogen–deuterium self‐exchange in hydrogen sulfide and hydrogen selenide have been studied over a wide range of deuterium atom percent using a pulsed‐molecular‐beam quadrupole mass filter. KHDS was found to be 3.88 ± 0.03 at 24.0 ± 0.4°C and KHDSe was found to be 3.92 ± 0.04 at 22 ± 1°C. The experimental results agree with calculations from spectroscopic data to within 1%. It is shown that equilibrium constants for self‐exchange reactions in systems where two hydrogenic species are exchanged tend toward the geometric mean value of K = 4 in the series H2O:H2S:H2Se as expected from theory.

空気中の微量セレン化水素定量法を検討した.吸収液として18%遊離臭素を含む40%臭化水素酸を用い,労働環境許容濃度付近について吸収諸条件の検討を行なった結果,流速2l/minで吸収液20mlを入れたガラスフィルター付小形吸収ビン1本を用いれば,約98%以上捕集できた.吸収液中の残留遊離臭素は,加熱によらず,塩酸ヒドロキシルアミン溶液を加えて正しく脱色して除去し,また,3,3'-ジアミノベンジジン(以下DABと略記)を用いてセレンを比色定量するときの臭化物濃度による影響を検討し,定量法を確立した.本法によれば,50lの空気を採取することにより,労働環境の許容濃度をこえたかどうかを正しく知ることができる.

Exact expressions of the rotational energy including the centrifugal distortion effect were obtained for low JK states and applied to the analysis of the microwave spectra of the hydrogen selenide molecules observed by Jache et al. The molecular structure in the ground vibrational state was obtained by the method suggested previously by the authors. The results are as follows: rz(SeH) = 1.4754 ± 0.0007 A , rz(SeH) = 1.4711 ± 0.0003 A , < (HSeH)z = 90°51.5′ ± 3′ , < (DSeD)z = 90°52.6′ ± 1′ . The difference between rz(SeH) and rz(SeD) was well interpreted in terms of the anharmonicity of the vibration. A trial was done to determine the equilibrium molecular structure and anharmonicity constants for the stretching vibration from the rz structures of H2Se and D2Se. The result obtained is as follows: rz(SeH) = 1.4605 ± 0.003 A < (HSeH)e = 90°55′ ± 5′ F3(SeH) = (4.55 ± 0.8) × 1013dyne cm−2 .

The sensitivity for selenium determination with atomic absorption spectrophotometry is enhanced to a large extent by introducing hydrogen selenide gas into an argon-hydrogen flame. As a reducing agent, zinc granular and stannous chloride is successfully used for quantitative and rapid productions of hydrogen selenide from selenium(IV) solution. The sensitivity for 1 % absorption of the signal is estimated to be about 0.02 ppm of selenium.

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1. Titanium diselenide can be prepared by reacting selenium vapor with metallic titanium powder in an inert gas (helium, argon) stream at temperatures of 900–1200°C. 2. The reaction of hydrogen selenide with titanium yields stable titanium hydrides, and it is therefore impossible to produce the diselenide by this method. The Me-H bond is stronger than the Me-Se bond, as a result of which heating at 1300–1350°C completely fails to decompose the hydrides.

A rapid and sensitive method for the determination of arsenic, selenium, antimony and bismuth is described. These elements and their compounds are reduced to the corresponding hydride with sodium borohydride. The gaseous hydride is generated and collected by means of a generator fitted with a collapsible reservoir. The collected gases are subsequently introduced into an argon supported hydrogen flame and determined utilizing atomic absorption.

A comprehensive survey of the toxicological properties of selenium and tellurium and their compounds is presented. Although selenium has been used commercially for many years with no long-term systemic effects on industrial workers, selenium has long been regarded as a toxic substance. This belief stems principally from the well-known selenium poisoning of cattle caused by the consumption of seleniferous plants. Although elemental selenium is relatively nontoxic, certain selenium compounds are definitely toxic toward humans, the most seriously toxic being hydrogen selenide. Recent studies have indicated that selenium has an important role in animal nutrition and may be of particular value in the treatment of a number of deficiency diseases. Therefore it is important that reliable data be available on the toxic level of various selenium compounds toward different animal species. Considersbly less is known about the toxicity of tellurium and its compounds than about the toxicity of selenium. In general it appears that tellurium is less toxic than selenium, although there are exceptions to this rule. The recent developments on semiconducting tellurium compounds for thermoelectric applications have greatly increased the interest in the toxicity of tellurium and its compounds. A critical survey of the available data is presented in thismore » review.« less

$^{*}$Supported by the National Science Foundation. $^{1}$R.A. Hill and T.H. Edwards, J. Opt. Soc. Am. 53, 516, Abstract TB16. $^{2}$ R.A. Hill and T.H. Edwards, J. Mol. Spectroscopy 9, 494 (1962).

The polarographic reduction of piazothiol and piazoselenol, like that of benzofurazan, studied earlier, involves the participation of 6 electrons and the formation of ortho-phenylenediamine. The transfer of the first electron is preceded by a reversible protonation of the molecules. Hydrogen selenide formed in the reduction of piazoselenol gives the anodic wave of mercury ionization. Reducibility increases in the series: benzofurazan, piazothiol, piazoselenol in contrast to the increase in electronegativity of the key heteroatoms Se, S, O.

The epitaxial growth of aluminum nitride on the basal planes of hexagonal silicon carbide and aluminum nitride substrates has been studied using the ammonolysis of aluminum trichloride in a gas flow system. Adherent and continuous films were obtained under a wide range of experimental conditions, and the substrate temperature is the most influential factor determining the crystalline perfection of the deposit. In the temperature range 1200–1250°C, single crystal aluminum nitride films epitaxial with respect to the substrates, as thick as 25 μ, have been deposited reproducibly by using reactant mixtures with AlCl 3 /NH 3 molar ratios in the range of 5 × 10 −4 to 5 × 10 −3 . The use of mercury and hydrogen selenide as dopants has produced, respectively, p - and n -type aluminum nitride films.

The reaction of hydrogen selenide and pigment zinc oxide at room temperature has been investigated, using electron and x‐ray diffraction as a means of examining the reaction product. It was found that hydrogen selenide reacts with zinc oxide to form zinc selenide as a coating around the zinc oxide particles. After approximately one‐tenth of the zinc oxide is converted to zinc selenide by this surface reaction, the resulting coating of zinc selenide prevents the continuance of the reaction. Since the effective depth of penetration of electrons under the conditions of electron diffraction is much less than the average diameter of the pigment particles used in this investigation, the electron diffraction photograms necessarily arise largely from the particle surfaces. For this reason electron diffraction was successfully used to demonstrate that the reaction proceeded in the manner described. The paper illustrates the applicability of electron diffraction to the general problem of the examination of the surfaces of pigment particles.

For the rapid determination of SeH2, several granular gels which change colors when exposed to air containing small amount of SeH2 were investigated. Purified silica gel impregnated with gold chloride was found to be a most sensitive and stable reagent for SeH2. The gel was placed in a glass tubing and the sample air was drawn through the tube with constant flow rate, and the quantitative estimation was possible by measuring the length of colored zone. The mean relative error was within 5%. The measurable range were as follows : (1) SeH2 : 10-600 ppm when sample volume was 100 ml, and feeding time 3 min. (2) SeH2 : 1-100 ppm when sample volume was 500 ml, and feeding time 15 min.

The synthesis of 6-selenoguanosine (2) has been accomplished by a nucleophilic displacement of the chloro group from 2-amino-6-chloro-9-(β-D-ribofuranosyl)purine (1) with either selenourea or sodium hydrogen selenide. Treatment of 2 with Raney nickel has revealed that the seleno group can be removed much easier under these conditions than the corresponding mercapto group. Alkylation of 2 with several alkylating agents occurred at the exocyclic 6-seleno group to furnish several 6-alkylseleno-2-amino-9-(β-D-ribofuranosyl)purines. Nucleophilic displacement of the 6-benzylseleno group from 2-amino-6-benzylseleno-9-(β-D-ribofuranosyl)purine (3c) with sodium methoxide has been observed to occur at a faster rate than that observed for the corresponding 6-benzylmercapto derivative. A study on the relative stability between 2 and 6-seleno-9-(β-D-ribofuranosyl)purine toward basic conditions has revealed that the amino group at position two imparts an increase in stability.

The reaction between hydrogen gas and selenium dissolved in liquid tellurium is described as follows H2(g) + Se ⇄ H2Se(g) The kinetics of this reaction have been investigated at temperatures ranging between 525 and 625°C and at concentrations of selenium varying between 250 and 3,300 ppm. Under all conditions investigated the reaction was controlled by transport processes in one or other of the two phases depending on the relative values of the mass transfer coefficients. Subject to the assumption that the solution of selenium in tellurium is an ideal one the molecular diffusion coefficient of mixtures of hydrogen selenide in hydrogen, Dg, is approximately 1.6 cm.2 sec.−1 at 525°C, and 2.1 cm.2 sec.−1 at 625°C. In view of complicating factors accurate values of the diffusivity of selenium in liquid tellurium cannot be deducted from the experimental results. However, the value obtained from experimental measurements of 7.59 × 10−4 cm.2 sec.−1 at 525° is in reasonable agreement with the value of 9.85 × 10−5 cm.2 sec.−1 reported in the literature. On decrit comme suite la reaction entre l'hydrogene gazeux et le selenium dissous dans le tellure liquide H2(g) + Se ⇄H2Se (g) On a etudie la cinetique de la dite reaction a des temperatures comprises entre 525 et 625°C et pour des concentrations de selenium variant entre 250 et 3,300 ppm. Dans toutes les conditions de l'etude on a regle la reaction por des procedes de transport dans Tune ou l'autre phase, selon les valeurs relatives des coefficients de transforts de masse. En supposant que la solution du selenium dans le tellure etait ideale, le coefficient Dg de diffusion moleculaire des melanges d'hydrure de selenium dans l'hydrogene etait approximativement 1.6 cm.2 sec.−1 a 525°C et 2.1 cm.2 sec.−1 a 625°C. On n'a pu, a cause de complications, etablir des valeurs precises pour la diffusivite du selenium en utilisant les resultats experimentaux; toutefois la valeur de 7.59 × 10−4 cm.2 a 525°C obtenue par des mesures experimentales a concorde assez bien avec celle de 9.85 × 10−5 cm.2 sec.−1 qu'on a rapportee dans certaines publications.

The infra‐red spectra of H2Se, D2Se and HDSe have been measured and the positions of the three fundamental frequencies for each molecule have been determined. These are; for H2Se v1 = 2260 cm—1, v2 = 1074 cm—1, v3 = 2350 cm—1; for D2Se, v1 = 1630 cm—1, v2 = 745 cm—1, v3 = 1696 cm—1; for HDSe, v1 = 1691 cm—1, v2 = 905 cm—1 and v3 = 2352 cm—1. Interpretation of the observed data has led to the adoption of an obtuse model where the H–Se–H bond angle is slightly in excess of 90°. The H–Se distances are evaluated to be 1.6A and the H–H distance is equal to 2.3A. The product relations of Redlich are made use of as a verification of a correct assignment of frequencies and for a correct determination of the band centers.

The decomposition of arsine, stibine, tin hydride, methane, germane, hydrogen selenide and nickel carbonyl on the surface of the corresponding elements have been discussed from the statistical mechanical view-point. As these decompositions are catalytic reactions of the simplest type, several reasonable assumptions enable us to calculate the rates of each elementary step of each reaction and hence to decide the rate-determining step in a semi a priori fashion. It is shown that the calculations impose definite limitations to the possible mode of decompositions of this kind.

Keilin1 reported the formation of a compound between hydrogen sulfide and ferrihemoglobin which appears to come into the category of a class of ferrihemoglobin compounds, the existence of which was predicted by Gamgee2 and termed “hemoferrides” by Barnard.3 Because of the close chemical, physical and toxicologic similarities of hydrogen sulfide to hydrogen selenide, we have studied the effects of the latter on various hemoglobin derivatives. The analogy between the two gases appears to extend to their behavior toward hemoglobin solutions, thus, treatment of ferrihemoglobin solutions with hydrogen selenide results in the formation of a compound which is spectroscopically similar to hydrogen sulfide ferrihemoglobin whereas the ferrihemochromogens are reduced by hydrogen selenide to the corresponding ferrohemochromogens.Experimental. I. Preparation of Solutions. 1. Ferrihemoglobin. Fresh erythrocyte suspensions (rat, dog, and human) of known oxygen capacity were hemolyzed with ether-saturated water and dilut...

In discussing the reactions of nitrite with blood pigment, Gamgee1 claimed priority on the discovery of the class of ferrihemoglobin derivatives typified by the cyanmethemoglobin of Kobert.2 Smith and Wolf3 discovered the azide and Haurewitz,4 the fluoride derivatives.On the basis of its potentiometric behavior, Barnard5 characterized alkaline ferrihemoglobin as the hydroxide of this class and predicted the ability of ferrihemoglobin to form polar valent compounds with many anions. Keilin6 described the hydrosulfide of ferrihemoglobin and in 1937, Barnard7 designated the class of derivatives as “hemo-ferrides” to emphasize their binary nature, i.e., they were salts of hydro-acids, exclusively. On the basis of the demonstration of the nitrile oxide structure of fulminic acid and the fulminates by Pauling and Hendricks,8 Barnard and Neitzel9 prepared a fulminate-ferrihemoglobin compound. Hydrogen selenide derivatives of ferrihemoglobin and ferriheme were also prepared.10 Combinations between thiocyanate and...

The pattern coefficient of hydrogen selenide(H2Se)was measured by means of a quadrupole mass spectrometer in the pressure range from 10-8 to 10-6 Torr. The ratio of H2Se+:HSe+:Se+ has been found to be 100:37.0:89.1. The very high ratio of Se+in comparison with S+from H2S could be acceptable in the view-point of the energy of formation of Se+ ions from H2Se molecules.

The triethylamine salt of hydrogen selenide is an effective catalyst in the synthesis of formanilides by the reaction of aromatic amines with carbon monoxide under pressure.

A detoxification metabolite of selenite (X1) was isolated from rat urine by ionexchange chromatography and precipitation as the reineckate salt. X1 is very basic and its chloride salt was found to have a maximum molecular weight of 193.5 ± 15 per selenium. X1 cochromatographed with synthetic trimethyl selenide on paper in two solvent systems. The NMR spectra of trimethyl selenide and X1 both contained one peak at 3.25 ppm from tetramethyl silane. Trimethyl selenide and X1 both gave mass peaks for dimethyl selenide, methyl selenide, and hydrogen selenide when heated to 175–180 ° in a mass spectrometer. From the data presented, it seems most likely that the major urinary detoxification metabolite of selenite is trimethyl selenide.

Uranium-aluminum compounds were prepared by solidsolid reaction of aluminum powder and uranium hydride; x-ray-diffraction patterns showed that single phases of UAl/sub 2/, UAl/sub 3/, and UAl/sub 4/ could be achieved. The uranium-beryllium compound, UBe/sub 1//sub 3/, was prepared by solid-solid reaction of berylllum powder and uranium hydride. The uranium-boron compounds, UB/sub 2/ UB/sub 4/, and UB/sub 1//sub 2/ were prepared by solid reaction, and single borides were obtained; carbon contamination was especially serious in these samples. The uranium-carbon compounds, UC and UC/sub 2/, were prepared by solid-solid reactlons to 1200 deg C; the x-ray-diffraction patterns showed a mixture of phases, and higher temperatures are probably required. The uranium- nitrogen compounds, UN and UN/sub 2/, were prepared by reaction of uranium with ammonia at 850 deg C for UN/sub 2/ and subsequent heating of that product in vacuum for UN. The uranium-selenium compounds, USe and USe/sub 2/, were prepared in very small samples; the violence of the reaction of selenium with uranium hydride and the lack of availability of hydrogen selenide limits the size of preparations. The uranium-silicon samples, USi/sub 2/ and USi/sub 3/ were prepared by solid-solid reaction of UH/sub 3/ and 8i; numerous attempts were made to prepare U8i. One of the USi/sub 2/ samples was alpha -USi/sub 2/ and the other was beta -USi/sub 2/. The uranium-sulfur compounds, US and US/sub 2/, were prepared; US/sub 2/ was prepared by forming unanium hydride in a flow furnace and then reacting the hydride with hydrogen sulfide; US was prepared by reacting some of the US/sub 2/ with UH/sub 3/. (auth)

The reactions of Pt(PPh3)n(n= 2 or 3) with H2M, HMPh, and M (M = S or Se) to form adducts have been studied. The reactivity of the products towards soft and hard reagents has been investigated and compared with that of related H2M, HMPh, and M adducts of some RhI and IrI triphenylphosphine complexes. The results agree with the proposed mechanisms of poisoning of metal surfaces by species such as H2M or M.

Digermyl selenide and digermyl telluride have been prepared by exchange with the analogous silyl compounds; the selenide has also been made from digermylcarbodi-imide and hydrogen selenide. The compounds were characterised spectroscopically and by their reaction with hydrogen iodide. The vibrational spectra of the compounds indicate that, as expected, the heavy-atom skeletons are bent at the Group VI atoms.

SELENIUM and its compounds are used extensively in the arts and in industry, but relatively little has been reported in this new field. The element selenium was discovered by Berzelius in 1817; it is intimately related to sulfur, arsenic and tellurium and shares many of their physical and chemical properties. In addition to the element itself, some of the commonly used compounds are: hydrogen selenide; sodium selenide; selenium dioxide; selenium oxychloride; selenious acid and its salts sodium and potassium selenite, and selenic acid and its salt sodium selenate. The compounds of selenium are used in the manufacture of ruby glass, as well as in decolorizing glass. They find a place in the production of pigments for paint and ink and in coloring plastics. In metallurgy, they are used in the manufacture of stainless steel and copper alloys. They are also used extensively in the rubber industry, in fireproofing of electric

Contrary to some textbook statements, hydrogen selenide is found to be quite stable thermally.

IN connexion with previous determinations of the structure of solid α-nitrogen1 and of solid carbon monoxide, we have during last year carried out a structure analysis of solid hydrogen sulphide, hydrogen selenide, and nitrogen dioxide by means of powder diagrams obtained with an apparatus described in a previous paper. A more complete description of the results will appear elsewhere, but I want here briefly to state some of the principal results.