Organogermanium Compound on:
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Triphenylgermanol (Ph3GeOH) is known, existing as colorless solid. Like the isostructural
Datasheet commercial supplier
* Tetraethylgermaniu
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* Tris(trimethylsilyl)germanium hydrid
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Organogermanium compounds are organometallic compounds containing a
hyperconjugation effect known as the beta-silicon effect Sielectronegativity
Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the ...
2.55 − 2.01 = 0.54) and the combined stabilizing effect on the α-carbonion by the carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...
to germanium
Germanium is a chemical element with the 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 neighbo ...
or hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
to germanium chemical bond
A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing o ...
. Organogermanium chemistry is the corresponding chemical science. Germanium shares group 14 in the periodic table with silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...
, tin and lead
Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...
, and not surprisingly the chemistry of organogermanium is in between that of organosilicon compounds and organotin compounds.
One reason that limited synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to:
Science
* Synthetic chemical or compound, produced by the process of chemical synthesis
* Synthetic o ...
value of organogermanium compound is costs of germanium compounds. On the other hand, germanium is advocated as a non-toxic alternative to many toxic organotin reagents. Compounds like tetramethylgermanium and tetraethylgermanium are used in the microelectronics industry as precursors for germanium dioxide chemical vapor deposition
Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films.
In typical CVD, the wafer (subst ...
.
The first organogermanium compound, tetraethylgermane, was synthesised by Winkler in 1887, by the reaction of germanium tetrachloride with diethylzinc. The organogermanium compound ''bis (2-Carboxyethylgermanium)sesquioxide'' was first reported in 1966.
Organogermanes
Organogermanes of the type R4Ge withalkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen.
The term ''alkyl'' is intentionally unspecific to include many possible substitutions.
An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloal ...
(R) groups are accessed through the cheapest available germanium precursor germanium tetrachloride and alkyl nucleophiles. The following trends are observed going down the carbon group: The nucleophilicity increases Siallyl
In organic chemistry, an allyl group is a substituent with the structural formula , where R is the rest of the molecule. It consists of a methylene bridge () attached to a vinyl group (). The name is derived from the scientific name for garlic, ...
group and the germanium atom. The germanium pendant of the Sakurai reaction was discovered in 1986:
:
The carbonyl
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containin ...
group in this reaction is activated with boron trifluoride
Boron trifluoride is the inorganic compound with the formula BF3. This pungent, colourless, and toxic gas forms white fumes in moist air. It is a useful Lewis acid and a versatile building block for other boron compounds.
Structure and bondin ...
.
Hydrides
Isobutylgermane (IBGe) (Me2CHCH2)GeH3 is the organogermanium hydride that is a high vapor pressure liquid germanium source for MOVPE. Isobutylgermane is currently investigated as safer and less hazardous alternative to toxic germane gas in microelectronic applications.Tris(trimethylsilyl)germanium hydride
Tris, or tris(hydroxymethyl)aminomethane, or known during medical use as tromethamine or THAM, is an organic compound with the formula (HOCH2)3CNH2, one of the twenty Good's buffers. It is extensively used in biochemistry and molecular biology a ...
(Me3Si)3GeH has been investigated as a non-toxic alternative to many tin hydrides such as tributyltin
Tributyltin (TBT) is an umbrella term for a class of organotin compounds which contain the (C4H9)3 Sn group, with a prominent example being tributyltin oxide. For 40 years TBT was used as a biocide in anti-fouling paint, commonly known as ...
hydride.
Other compounds
Triphenylgermanol (Ph3GeOH) is known, existing as colorless solid. Like the isostructural silanol
A silanol is a functional group in silicon chemistry with the connectivity Si–O–H. It is related to the hydroxy functional group (C–O–H) found in all alcohols. Silanols are often invoked as intermediates in organosilicon ...
, it engages in hydrogen bonding in the solid-state.
Many germanium reactive intermediate
In chemistry, a reactive intermediate or an intermediate is a short-lived, high-energy, highly reactive molecule. When generated in a chemical reaction, it will quickly convert into a more stable molecule. Only in exceptional cases can these com ...
s are known: germylene
Germylenes are a class of germanium(II) compounds with the general formula :GeR2. They are heavier carbene analogs. However, unlike carbenes, whose ground state can be either singlet or triplet depending on the substituents, germylenes have exclus ...
s ( carbene pendants), germyl free radical
A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing.
Ageing
Ailments of unknown cause
Biogerontology
Biological processes
Causes of death
Cellular processes
Gerontology
Life extension
Metabo ...
s, germynes ( carbyne pendants). Digermynnes only exist for extremely bulky substituents. Unlike alkyne
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Acetylene
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Propyne
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1-Butyne
In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and no ...
s, the C-Ge-Ge-C core of these Digermynnes is nonlinear, although they are planar. The Ge-Ge distance is 2.22 Å, and the Ge-Ge-C angles are 131°. Such compounds are prepared by the reduction of bulky arylgermanium(II) halides.Philip P. Power "Bonding and Reactivity of Heavier Group 14 Element Alkyne Analogues" Organometallics 2007, volume 26, pp 4362–4372.
As with silicon and contrasting with carbon, compounds containing Ge=C (germenes) and Ge=Ge (digermylenes) double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
s are rare. One example is the bulky derivatives of germabenzene
Germabenzene (C5H6Ge) is the parent representative of a group of chemical compounds containing in their molecular structure a benzene ring with a carbon atom replaced by a germanium atom. Germabenzene itself has been studied theoretically, and syn ...
, an analogue of benzene.
External links
* TetramethylgermaniuDatasheet commercial supplier
* Tetraethylgermaniu
Datasheet commercial supplier
* Tris(trimethylsilyl)germanium hydrid
Datasheet commercial supplier
References
{{ChemicalBondsToCarbon