Trimethylindium

Last updated
Trimethylindium
Trimethylindium-2D.png
Trimethylindium-from-xtal-3D-balls.png
Names
Preferred IUPAC name
Trimethylindium
Systematic IUPAC name
Trimethylindigane [1]
Other names
Trimethylindane, indium trimethyl
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.020.183 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 222-200-9
PubChem CID
UNII
  • InChI=1S/3CH3.In/h3*1H3; Yes check.svgY
    Key: IBEFSUTVZWZJEL-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/3CH3.In/h3*1H3;/rC3H9In/c1-4(2)3/h1-3H3
    Key: IBEFSUTVZWZJEL-SGQDGSKVAB
  • C[In](C)C
Properties
InC
3
H
9
Molar mass 159.922 g mol−1
AppearanceWhite, opaque crystals
Density 1.568 g cm−3 (at 20 °C)
Melting point 88 °C (190 °F; 361 K)
Boiling point 134 °C (273 °F; 407 K) (decomposes above 101 °C (214 °F; 374 K))
Reacts
Thermochemistry
150.5-169.7 kJ mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Pyrophoric
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg
Danger
H250, H260, H261, H314
P210, P222, P223, P231+P232, P260, P264, P280, P301+P330+P331, P302+P334, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P335+P334, P363, P370+P378, P402+P404, P405, P422, P501
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 ?)

Trimethylindium, often abbreviated to TMI or TMIn, is the organoindium compound with the formula In(CH3)3. It is a colorless, pyrophoric solid. [2] Unlike trimethylaluminium, but akin to trimethylgallium, TMI is monomeric. [3]

Contents

Preparation

TMI is prepared by the reaction of indium trichloride with methyl lithium. [2] [4]

InCl3 + 3 LiMe → Me3In.OEt2 + 3 LiCl

Properties

Compared to trimethylaluminium and trimethylgallium, InMe3 is a weaker Lewis acid. It forms adducts with secondary amines and phosphines. [5] A complex with the heterocyclic triazine ligand (PriNCH2)3 forms a complex with 6-coordinate In, where the C-In-C angles are 114°-117° with three long bonds to the tridentate ligand with N-In-N angles of 48.6° and long In-N bonds of 278 pm. [6]

Structure

In the gaseous state InMe3 is monomeric, with a trigonal planar structure, and in benzene solution it is tetrameric. [5] In the solid state there are two polymorphs, a tetragonal phase which is obtained, for example, by sublimation and a lower density rhombohedral phase discovered in 2005, [7] when InMe3 re-crystallised from hexane solution.

In the tetragonal form InMe3 is tetrameric as in benzene solution and there is bridging between tetramers to give an infinite network. Each indium atom is five coordinate, in a distorted trigonal planar configuration, the three shortest bonds,(ca. 216 pm ) are those in the equatorial plane, with longer axial bonds, 308 pm for the In-C bonds joining the InMe3 units to form the tetramers and 356 pm for the In-C linking the tetramers into an infinite network. [8] The solid state structures of GaMe3 and TlMe3 are similar. [8] The association in the solid state accounts for the high melting point of 89°-89.8 °C compared to triethylindium which melts at -32 °C. [5]

The rhombohedral form of InMe3 consists of cyclic hexamers with 12 membered (InC)6 rings in an extended chair conformation. The hexamers are interlinked into an infinite network. Indium atoms are five coordinate the equatorial In-C distances average 216.7pm almost identical to the average for the tetragonal form, and the axial bonds are 302.8pm joining the InMe3 units into hexamers and 313.4 pm linking the hexamers to form the infinite network. [7]

Application to microelectronics

Indium is a component of several compound semiconductors, including as InP, InAs, InN, InSb, GaInAs, InGaN, AlGaInP, AlInP, and AlInGaNP. These materials are prepared by metalorganic vapour phase epitaxy (MOVPE) and TMI is the preferred source for the indium component. High purity in TMI (99.9999% pure or greater) is essential for many of these applications. For some materials, electron mobilities are observed as high as 287,000 cm²/Vs at 77 K and 5400 cm²/Vs at 300 K, and background carrier concentration as low as 6×1013 cm−3. [9] [10]

Vapor pressure equation

The vapor pressure equation log P (Torr) = 10.98–3204/T (K) describes TMI within a wide range of MOVPE growth conditions. [11]

Safety

TMI is pyrophoric. [12]

Related Research Articles

<span class="mw-page-title-main">Indium</span> Chemical element, symbol In and atomic number 49

Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. Indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Chemically, indium is similar to gallium and thallium, and it is largely intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods. They named it for the indigo blue line in its spectrum. Indium was isolated the next year.

<span class="mw-page-title-main">Organometallic chemistry</span> Study of organic compounds containing metal(s)

Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like carbon monoxide, cyanide, or carbide, are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds, though strictly speaking, they are not necessarily organometallic. The related but distinct term "metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates, alkoxides, dialkylamides, and metal phosphine complexes are representative members of this class. The field of organometallic chemistry combines aspects of traditional inorganic and organic chemistry.

<span class="mw-page-title-main">Aluminium gallium arsenide</span> Semiconductor material

Aluminium gallium arsenide (AlxGa1−xAs) is a semiconductor material with very nearly the same lattice constant as GaAs, but a larger bandgap. The x in the formula above is a number between 0 and 1 - this indicates an arbitrary alloy between GaAs and AlAs.

A substance is pyrophoric if it ignites spontaneously in air at or below 54 °C (129 °F) or within 5 minutes after coming into contact with air. Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or nitrogen. Class D fire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolicity, in which two compounds spontaneously ignite when mixed.

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

Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2(CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially important compound, closely related to triethylaluminium.

<span class="mw-page-title-main">Metalorganic vapour-phase epitaxy</span> Method of producing thin films (polycrystalline and single crystal)

Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. It is a process for growing crystalline layers to create complex semiconductor multilayer structures. In contrast to molecular-beam epitaxy (MBE), the growth of crystals is by chemical reaction and not physical deposition. This takes place not in vacuum, but from the gas phase at moderate pressures. As such, this technique is preferred for the formation of devices incorporating thermodynamically metastable alloys, and it has become a major process in the manufacture of optoelectronics, such as Light-emitting diodes. It was invented in 1968 at North American Aviation Science Center by Harold M. Manasevit.

<span class="mw-page-title-main">Indium gallium nitride</span> Chemical compound

Indium gallium nitride is a semiconductor material made of a mix of gallium nitride (GaN) and indium nitride (InN). It is a ternary group III/group V direct bandgap semiconductor. Its bandgap can be tuned by varying the amount of indium in the alloy. InxGa1−xN has a direct bandgap span from the infrared for InN to the ultraviolet of GaN. The ratio of In/Ga is usually between 0.02/0.98 and 0.3/0.7.

Aluminium gallium indium phosphide is a semiconductor material that provides a platform for the development of novel multi-junction photovoltaics and optoelectronic devices, as it spans a direct bandgap from deep ultraviolet to infrared.

Aluminium gallium nitride (AlGaN) is a semiconductor material. It is any alloy of aluminium nitride and gallium nitride.

<span class="mw-page-title-main">Indium(III) chloride</span> Chemical compound

Indium(III) chloride is the chemical compound with the formula InCl3. This salt is a white, flaky solid with applications in organic synthesis as a Lewis acid. It is also the most available soluble derivative of indium. This is one of three known indium chlorides.

Aluminium indium arsenide, also indium aluminium arsenide or AlInAs (AlxIn1−xAs), is a semiconductor material with very nearly the same lattice constant as GaInAs, but a larger bandgap. The x in the formula above is a number between 0 and 1 - this indicates an arbitrary alloy between InAs and AlAs.

Indium(III) sulfate (In2(SO4)3) is a sulfate salt of the metal indium. It is a sesquisulfate, meaning that the sulfate group occurs 11/2 times as much as the metal. It may be formed by the reaction of indium, its oxide, or its carbonate with sulfuric acid. An excess of strong acid is required, otherwise insoluble basic salts are formed. As a solid indium sulfate can be anhydrous, or take the form of a pentahydrate with five water molecules or a nonahydrate with nine molecules of water. Indium sulfate is used in the production of indium or indium containing substances. Indium sulfate also can be found in basic salts, acidic salts or double salts including indium alum.

<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">Trimethylgallium</span> Chemical compound

Trimethylgallium, often abbreviated to TMG or TMGa, is the organogallium compound with the formula Ga(CH3)3. It is a colorless, pyrophoric liquid. Unlike trimethylaluminium, TMG adopts a monomeric structure. When examined in detail, the monomeric units are clearly linked by multiple weak Ga---C interactions, reminiscent of the situation for trimethylindium.

Zinc arsenide (Zn3As2) is a binary compound of zinc with arsenic which forms gray tetragonal crystals. It is an inorganic semiconductor with a band gap of 1.0 eV.

<span class="mw-page-title-main">Organogallium chemistry</span> Chemistry of Organogallium compounds

Organogallium chemistry is the chemistry of organometallic compounds containing a carbon to gallium (Ga) chemical bond. Despite their high toxicity, organogallium compounds have some use in organic synthesis. The compound trimethylgallium is of some relevance to MOCVD as a precursor to gallium arsenide via its reaction with arsine at 700 °C:

<span class="mw-page-title-main">Organoindium chemistry</span> Chemistry of compounds with a carbon to indium bond

Organoindium chemistry is the chemistry of compounds containing In-C bonds. The main application of organoindium chemistry is in the preparation of semiconducting components for microelectronic applications. The area is also of some interest in organic synthesis. Most organoindium compounds feature the In(III) oxidation state, akin to its lighter congeners Ga(III) and B(III).

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

Gallane, also systematically named trihydridogallium, is an inorganic compound of gallium with the chemical formula GaH
3
. It is a photosensitive, colourless gas that cannot be concentrated in pure form. Gallane is both the simplest member of the gallanes, and the prototype of the monogallanes. It has no economic uses, and is only intentionally produced for academic reasons.

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

Indium trihydride is an inorganic compound with the chemical formula (InH
3
). It has been observed in matrix isolation and laser ablation experiments. Gas phase stability has been predicted. The infrared spectrum was obtained in the gas phase by laser ablation of indium in presence of hydrogen gas InH3 is of no practical importance.

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

Triethylgallium is the organogallium compound with the formul Ga(C2H5)3. Also called TEGa, it is a metalorganic source of gallium for metalorganic vapour phase epitaxy (MOVPE) of compound semiconductors. It is a colorless pyrophoric liquid, typically handled with air-free techniques.

References

  1. "Trimethylindium - PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information. 27 March 2005. Descriptors Computed from Structure. Retrieved 21 September 2011.
  2. 1 2 Bradley, D. C.; Chudzynska, H. C.; Harding, I. S. (1997). "Trimethylindium and Trimethylgallium". Inorganic Syntheses. 31: 67–74. doi:10.1002/9780470132623.ch8.
  3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 262. ISBN   978-0-08-037941-8.
  4. Main Group compounds in Inorganic Syntheses, vol 31, Schultz, Neumayer, Marks; Ed., Alan H. Cowley, John Wiley & Sons, Inc., 1997, ISBN   0471152889
  5. 1 2 3 CVD of compound semiconductors, Precursor Synthesis, Development and Applications, Anthony C. Jones, Paul O'Brien, John Wiley & Sons, 2008, ISBN   3527292942
  6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 263. ISBN   978-0-08-037941-8.
  7. 1 2 Lewiński, Janusz; Zachara, Janusz; Starowieyski, Kazimierz B.; Justyniak, Iwona; Lipkowski, Janusz; Bury, Wojciech; Kruk, Przemysław; Woźniak, Robert (2005). "A Second Polymorphic Form of Trimethylindium: Topology of Supramolecular Architectures of Group 13 Trimethyls". Organometallics. 24 (20): 4832–4837. doi:10.1021/om050386s. ISSN   0276-7333.
  8. 1 2 Inorganic Chemistry, (2d edition), Catherine E. Housecroft, Alan G. Sharpe, Pearson Education, 2005, ISBN   0130399132 , ISBN   978-0130399137
  9. Shenai, Deo V.; Timmons, Michael L.; Dicarlo, Ronald L.; Lemnah, Gregory K.; Stennick, Robert S. (2003). "Correlation of vapor pressure equation and film properties with trimethylindium purity for the MOVPE grown III–V compounds". Journal of Crystal Growth. 248: 91. doi:10.1016/S0022-0248(02)01854-7.
  10. Shenai, Deodatta V.; Timmons, Michael L.; Dicarlo, Ronald L.; Marsman, Charles J. (2004). "Correlation of film properties and reduced impurity concentrations in sources for III/V-MOVPE using high-purity trimethylindium and tertiarybutylphosphine". Journal of Crystal Growth. 272: 603. doi:10.1016/j.jcrysgro.2004.09.006.
  11. Shenai-Khatkhate, Deodatta V.; Dicarlo, Ronald L.; Ware, Robert A. (2008). "Accurate vapor pressure equation for trimethylindium in OMVPE". Journal of Crystal Growth. 310 (7–9): 2395. doi:10.1016/j.jcrysgro.2007.11.196.
  12. Chemistry of Materials (2000); doi : 10.1021/cm990497f