Germane

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Germane
Germane-2D-dimensions.png
Ball-and-stick model of the germane molecule Germane-3D-balls-A.png
Ball-and-stick model of the germane molecule
Space-filling model of the germane molecule Germane-3D-vdW.png
Space-filling model of the germane molecule
  Germanium, Ge
  Hydrogen, H
Names
IUPAC name
Germane
Other names
Germanium tetrahydride
Germanomethane
Monogermane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.055 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 231-961-6
587
KEGG
PubChem CID
RTECS number
  • LY4900000
UNII
UN number 2192
  • InChI=1S/GeH4/h1H4 Yes check.svgY
    Key: QUZPNFFHZPRKJD-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/GeH4/h1H4
    Key: QUZPNFFHZPRKJD-UHFFFAOYAE
  • [H][Ge]([H])([H])[H]
Properties
GeH4
Molar mass 76.62 g/mol
AppearanceColorless gas
Odor Pungent [1]
Density 3.3 kg/m3
Melting point −165 °C (−265 °F; 108 K)
Boiling point −88 °C (−126 °F; 185 K)
Low
Vapor pressure >1 atm [1]
Viscosity 17.21 μPa·s
(theoretical estimate) [2]
Structure
Tetrahedral
0  D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Toxic, flammable, may ignite spontaneously in air
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-bottle.svg GHS-pictogram-skull.svg GHS-pictogram-exclam.svg
Danger
H220, H280, H302, H330
P210, P260, P264, P270, P271, P284, P301+P312, P304+P340, P310, P320, P330, P377, P381, P403, P403+P233, P405, P410+P403, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
4
4
3
NIOSH (US health exposure limits):
PEL (Permissible)
None [1]
REL (Recommended)
TWA 0.2 ppm (0.6 mg/m3) [1]
IDLH (Immediate danger)
N.D. [1]
Safety data sheet (SDS) ICSC 1244
Related compounds
Related compounds
Methane
Silane
Stannane
Plumbane
Germyl
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Germane is the chemical compound with the formula Ge H4, and the germanium analogue of methane. It is the simplest germanium hydride and one of the most useful compounds of germanium. Like the related compounds silane and methane, germane is tetrahedral. It burns in air to produce GeO2 and water. Germane is a group 14 hydride.

Contents

Occurrence

Germane has been detected in the atmosphere of Jupiter. [3]

Synthesis

Germane is typically prepared by reduction of germanium oxides, notably germanates, with hydride reagents such as sodium borohydride, potassium borohydride, lithium borohydride, lithium aluminium hydride, sodium aluminium hydride. The reaction with borohydrides is catalyzed by various acids and can be carried out in either aqueous or organic solvent. On laboratory scale, germane can be prepared by the reaction of Ge(IV) compounds with these hydride reagents. [4] [5] A typical synthesis involved the reaction of sodium germanate with potassium borohydride. [6]

NaHGeO3 + KBH4 + H2O → KGeH3 + KB(OH)4
KGeH3 + HO2CCH3 → GeH4 + KO2CCH3

Other methods for the synthesis of germane include electrochemical reduction and a plasma-based method. [7] The electrochemical reduction method involves applying voltage to a germanium metal cathode immersed in an aqueous electrolyte solution and an anode counter-electrode composed of a metal such as molybdenum or cadmium. In this method, germane and hydrogen gases evolve from the cathode while the anode reacts to form solid molybdenum oxide or cadmium oxides. The plasma synthesis method involves bombarding germanium metal with hydrogen atoms (H) that are generated using a high frequency plasma source to produce germane and digermane.

Reactions

Germane is weakly acidic. In liquid ammonia GeH4 is ionised forming NH4+ and GeH3. [8] With alkali metals in liquid ammonia GeH4 reacts to give white crystalline MGeH3 compounds. The potassium (potassium germyl or potassium trihydrogen germanide KGeH3) and rubidium compounds (rubidium germyl or rubidium trihydrogen germanide RbGeH3) have the sodium chloride structure implying a free rotation of the trihydrogen germanide anion GeH3, the caesium compound, caesium germyl or caesium trihydrogen germanide CsGeH3 in contrast has the distorted sodium chloride structure of TlI. [8]

Use in semiconductor industry

The gas decomposes near 600K (327°C; 620°F) to germanium and hydrogen. Because of its thermal lability, germane is used in the semiconductor industry for the epitaxial growth of germanium by MOVPE or chemical beam epitaxy. [9] Organogermanium precursors (e.g. isobutylgermane, alkylgermanium trichlorides, and dimethylaminogermanium trichloride) have been examined as less hazardous liquid alternatives to germane for deposition of Ge-containing films by MOVPE. [10]

Safety

Germane is a highly flammable, potentially pyrophoric, [11] and a highly toxic gas. In 1970, the American Conference of Governmental Industrial Hygienists (ACGIH) published the latest changes and set the occupational exposure threshold limit value at 0.2 ppm for an 8-hour time weighted average. [12] The LC50 for rats at 1 hour of exposure is 622 ppm. [13] Inhalation or exposure may result in malaise, headache, dizziness, fainting, dyspnea, nausea, vomiting, kidney injury, and hemolytic effects. [14] [15] [16]

The US Department of Transportation hazard class is 2.3 Poisonous Gas. [12]

Related Research Articles

<span class="mw-page-title-main">Alkali metal</span> Group of highly reactive chemical elements

The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element.

<span class="mw-page-title-main">Germanium</span> Chemical element, symbol Ge and atomic number 32

Germanium is a chemical element; it has symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature.

<span class="mw-page-title-main">Hydride</span> Molecule with a hydrogen bound to a more electropositive element or group

In chemistry, a hydride is formally the anion of hydrogen (H), a hydrogen atom with two electrons. The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. For inorganic chemists, hydrides refer to compounds and ions in which hydrogen is covalently attached to a less electronegative element. In such cases, the H centre has nucleophilic character, which contrasts with the protic character of acids. The hydride anion is very rarely observed.

<span class="mw-page-title-main">Arsine</span> Chemical compound

Arsine (IUPAC name: arsane) is an inorganic compound with the formula AsH3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications in the semiconductor industry and for the synthesis of organoarsenic compounds. The term arsine is commonly used to describe a class of organoarsenic compounds of the formula AsH3−xRx, where R = aryl or alkyl. For example, As(C6H5)3, called triphenylarsine, is referred to as "an arsine".

<span class="mw-page-title-main">Diborane</span> Chemical compound

Diborane(6), commonly known as diborane, is the chemical compound with the formula B2H6. It is a toxic, colorless, and pyrophoric gas with a repulsively sweet odor. Given its simple formula, borane is a fundamental boron compound. It has attracted wide attention for its electronic structure. Several of its derivatives are useful reagents.

<span class="mw-page-title-main">Stibine</span> Chemical compound

Stibine (IUPAC name: stibane) is a chemical compound with the formula SbH3. A pnictogen hydride, this colourless, highly toxic gas is the principal covalent hydride of antimony, and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 170.7 pm (1.707 Å). This gas has an offensive smell like hydrogen sulfide (rotten eggs).

<span class="mw-page-title-main">Antimony trioxide</span> Chemical compound

Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in nature as the very rare mineral stibioclaudetite.

<span class="mw-page-title-main">Lithium hydride</span> Chemical compound

Lithium hydride is an inorganic compound with the formula LiH. This alkali metal hydride is a colorless solid, although commercial samples are grey. Characteristic of a salt-like (ionic) hydride, it has a high melting point, and it is not soluble but reactive with all protic organic solvents. It is soluble and nonreactive with certain molten salts such as lithium fluoride, lithium borohydride, and sodium hydride. With a molar mass of 7.95 g/mol, it is the lightest ionic compound.

Organogermanium chemistry is the science of chemical species containing one or more C–Ge bonds. Germanium shares group 14 in the periodic table with carbon, silicon, tin and lead. Historically, organogermanes are considered as nucleophiles and the reactivity of them is between that of organosilicon and organotin compounds. Some organogermanes have enhanced reactivity compared with their organosilicon and organoboron analogues in some cross-coupling reactions.

<span class="mw-page-title-main">Isobutylgermane</span> Chemical compound

Isobutylgermane (IBGe, Chemical formula: (CH3)2CHCH2GeH3, is an organogermanium compound. It is a colourless, volatile liquid that is used in MOVPE (Metalorganic Vapor Phase Epitaxy) as an alternative to germane. IBGe is used in the deposition of Ge films and Ge-containing thin semiconductor films such as SiGe in strained silicon application, and GeSbTe in NAND Flash applications.

<span class="mw-page-title-main">Plumbane</span> Chemical compound

Plumbane is an inorganic chemical compound with the chemical formula PbH4. It is a colorless gas. It is a metal hydride and group 14 hydride composed of lead and hydrogen. Plumbane is not well characterized or well known, and it is thermodynamically unstable with respect to the loss of a hydrogen atom. Derivatives of plumbane include lead tetrafluoride, PbF4, and tetraethyllead, (CH3CH2)4Pb.

Zinc hydride is an inorganic compound with the chemical formula ZnH2. It is a white, odourless solid which slowly decomposes into its elements at room temperature; despite this it is the most stable of the binary first row transition metal hydrides. A variety of coordination compounds containing Zn–H bonds are used as reducing agents, however ZnH2 itself has no common applications.

<span class="mw-page-title-main">Germanate</span> Chemical compound

In chemistry, germanate is a compound containing an oxyanion of germanium. In the naming of inorganic compounds it is a suffix that indicates a polyatomic anion with a central germanium atom, for example potassium hexafluorogermanate, K2GeF6.

<span class="mw-page-title-main">Digermane</span> Chemical compound

Digermane is an inorganic compound with the chemical formula Ge2H6. One of the few hydrides of germanium, it is a colourless liquid. Its molecular geometry is similar to ethane.

<span class="mw-page-title-main">Sodium germanate</span> Chemical compound

Sodium germanate is an inorganic compound with the chemical formula Na2GeO3. It exists as a colorless solid. Sodium germanate is primarily used for the synthesis of other germanium compounds.

Group 14 hydrides are chemical compounds composed of hydrogen atoms and group 14 atoms.

Germyl, trihydridogermanate(1-), trihydrogermanide, trihydridogermyl or according to IUPAC Red Book: germanide is an anion containing germanium bounded with three hydrogens, with formula GeH−3. Germyl is the IUPAC term for the –GeH3 group. For less electropositive elements the bond can be considered covalent rather than ionic as "germanide" indicates. Germanide is the base for germane when it loses a proton.

Germanium compounds are chemical compounds formed by the element germanium (Ge). Germanium is insoluble in dilute acids and alkalis but dissolves slowly in hot concentrated sulfuric and nitric acids and reacts violently with molten alkalis to produce germanates ([GeO
3
]2−
). Germanium occurs mostly in the oxidation state +4 although many +2 compounds are known. Other oxidation states are rare: +3 is found in compounds such as Ge2Cl6, and +3 and +1 are found on the surface of oxides, or negative oxidation states in germanides, such as −4 in Mg
2
Ge
. Germanium cluster anions (Zintl ions) such as Ge42−, Ge94−, Ge92−, [(Ge9)2]6− have been prepared by the extraction from alloys containing alkali metals and germanium in liquid ammonia in the presence of ethylenediamine or a cryptand. The oxidation states of the element in these ions are not integers—similar to the ozonides O3.

<span class="mw-page-title-main">Silylgermane</span> Chemical compound

Silylgermane is an inorganic compound with the chemical formula H3Si−GeH3. It is a colorless gas with an unpleasant odor. It is unstable in air. It is very flammable, very toxic and corrosive. It reacts with alkali liberating hydrogen.

References

  1. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0300". National Institute for Occupational Safety and Health (NIOSH).
  2. Yaws, Carl L. (1997), Handbook Of Viscosity: Volume 4: Inorganic Compounds And Elements, Gulf Professional Publishing, ISBN   978-0123958501
  3. Kunde, V.; Hanel, R.; Maguire, W.; Gautier, D.; Baluteau, J. P.; Marten, A.; Chedin, A.; Husson, N.; Scott, N. (1982). "The tropospheric gas composition of Jupiter's north equatorial belt (NH3, PH3, CH3D, GeH4, H2O) and the Jovian D/H isotopic ratio". Astrophysical Journal. 263: 443–467. Bibcode:1982ApJ...263..443K. doi:10.1086/160516.
  4. W. L. Jolly "Preparation of the Volatile Hydrides of Groups IVA and VA by Means of Aqueous Hydroborate" Journal of the American Chemical Society 1961, volume 83, pp. 335-7.
  5. US Patent 4,668,502
  6. Girolami, G. S.; Rauchfuss, T. B.; Angelici, R. J. (1999). Synthesis and Technique in Inorganic Chemistry. Mill Valley, CA: University Science Books.
  7. US Patent 7,087,102 (2006)
  8. 1 2 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  9. Venkatasubramanian, R.; Pickett, R. T.; Timmons, M. L. (1989). "Epitaxy of germanium using germane in the presence of tetramethylgermanium". Journal of Applied Physics . 66 (11): 5662–5664. Bibcode:1989JAP....66.5662V. doi:10.1063/1.343633.
  10. Woelk, E.; Shenai-Khatkhate, D. V.; DiCarlo, R. L. Jr.; Amamchyan, A.; Power, M. B.; Lamare, B.; Beaudoin, G.; Sagnes, I. (2006). "Designing Novel Organogermanium MOVPE Precursors for High-purity Germanium Films". Journal of Crystal Growth. 287 (2): 684–687. Bibcode:2006JCrGr.287..684W. doi:10.1016/j.jcrysgro.2005.10.094.
  11. Brauer, 1963, Vol.1, 715
  12. 1 2 Praxair MSDS Archived 2012-05-08 at the Wayback Machine accessed Sep. 2011
  13. NIOSH Germane Registry of Toxic Effects of Chemical Substances (RTECS)accessed Sep. 2011
  14. Gus'kova, E. I. (1974). "K toksikologii Gidrida Germaniia" [Toxicology of germanium hydride]. Gigiena Truda I Professionalnye Zabolevaniia (in Russian). 18 (2): 56–57. PMID   4839911.
  15. US EPA Germane
  16. Paneth, F.; Joachimoglu, G. (1924). "Über die pharmakologischen Eigenschaften des Zinnwasserstoffs und Germaniumwasserstoffs" [About the pharmacological characteristics of tin hydride and germanium hydride]. Berichte der Deutschen Chemischen Gesellschaft (in German). 57 (10): 1925–1930. doi:10.1002/cber.19240571027.