Silicon monoxide

Last updated
Silicon monoxide
Silicon monoxide.jpg
Silicon-monoxide-3D-balls.png
Names
Preferred IUPAC name
Silicon monoxide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.030.198 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 233-232-8
382
MeSH Silicon+monoxide
PubChem CID
UNII
  • InChI=1S/H3OSi/c1-2/h2H3 X mark.svgN
    Key: UXMAWJKSGBRJKV-UHFFFAOYSA-N X mark.svgN
  • InChI=1/OSi/c1-2
    Key: LIVNPJMFVYWSIS-UHFFFAOYAO
  • InChI=1S/OSi/c1-2
    Key: LIVNPJMFVYWSIS-UHFFFAOYSA-N
  • [O+]#[Si-]
Properties
SiO
Molar mass 44.08 g/mol
Appearancebrown-black glassy solid
Density 2.13 g/cm3
Melting point 1,702 °C (3,096 °F; 1,975 K)
Boiling point 1,880 °C (3,420 °F; 2,150 K)
insoluble
Hazards
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Flash point Non-flammable
Related compounds
Other anions
Silicon sulfide
Silicon selenide
Silicon telluride
Other cations
Carbon monoxide
Germanium(II) oxide
Tin(II) oxide
Lead(II) oxide
Related silicon oxides
Silicon dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Silicon monoxide is the chemical compound with the formula SiO where silicon is present in the oxidation state +2. In the vapour phase, it is a diatomic molecule. [1] It has been detected in stellar objects [2] and has been described as the most common oxide of silicon in the universe. [3]

Contents

Solid form

When SiO gas is cooled rapidly, it condenses to form a brown/black polymeric glassy material, (SiO)n, which is available commercially and used to deposit films of SiO. Glassy (SiO)n is air and moisture sensitive.[ clarification needed ][ citation needed ]

Oxidation

Its surface readily oxidizes in air at room temperature, giving an SiO2 surface layer that protects the material from further oxidation. However, (SiO)n irreversibly disproportionates into SiO2 and Si in a few hours between 400 °C and 800 °C and very rapidly between 1,000 °C and 1,440 °C, although the reaction does not go to completion. [4]

Production

The first precise report on the formation of SiO was in 1887 [5] by the chemist Charles F. Maybery (1850–1927) at the Case School of Applied Science in Cleveland. Maybery claimed that SiO formed as an amorphous greenish-yellow substance with a vitreous luster when silica was reduced with charcoal in the absence of metals in an electric furnace. [6] The substance was always found at the interface between the charcoal and silica particles.

By investigating some of the chemical properties of the substance, its specific gravity, and a combustion analysis, Maybery deduced that the substance must be SiO. The equation representing the partial chemical reduction of SiO2 with C can be represented as:

SiO
2 + C ⇌ SiO + CO

Complete reduction of SiO2 with twice the amount of carbon yields elemental silicon and twice the amount of carbon monoxide. In 1890, the German chemist Clemens Winkler (the discoverer of germanium) was the first to attempt to synthesize SiO by heating silicon dioxide with silicon in a combustion furnace. [7]

SiO
2 + Si ⇌ 2 SiO

However, Winkler was not able to produce the monoxide since the temperature of the mixture was only around 1000 °C. The experiment was repeated in 1905 by Henry Noel Potter (1869–1942), a Westinghouse engineer. Using an electric furnace, Potter was able to attain a temperature of 1700 °C and observe the generation of SiO. [5] Potter also investigated the properties and applications of the solid form of SiO. [8] [9]

Gaseous form

Because of the volatility of SiO, silica can be removed from ores or minerals by heating them with silicon to produce gaseous SiO in this manner. [1] However, due to the difficulties associated with accurately measuring its vapor pressure, and because of the dependency on the specifics of the experimental design, various values have been reported in the literature for the vapor pressure of SiO (g). For the pSiO above molten silicon in a quartz (SiO2) crucible at the melting point of silicon, one study yielded a value of 0.002 atm. [10] For the direct vaporization of pure, amorphous SiO solid, 0.001 atm has been reported. [11] For a coating system, at the phase boundary between SiO2 and a silicide, 0.01 atm was reported. [12]

Silica itself, or refractories containing SiO2, can be reduced with H2 or CO at high temperatures, e.g.: [13]

SiO
2(s) + H
2(g) ⇌ SiO(g) + H
2O(g)

As the SiO product volatilizes off (is removed), the equilibrium shifts to the right, resulting in the continued consumption of SiO2. Based on the dependence of the rate of silica weight loss on the gas flow rate normal to the interface, the rate of this reduction appears to be controlled by convective diffusion or mass transfer from the reacting surface. [14] [15]

Gaseous (molecular) form

Silicon monoxide molecules have been trapped in an argon matrix cooled by helium. In these conditions, the SiO bond length is between 148.9 pm [3] and 151 pm. [16] This bond length is similar to the length of Si=O double bonds (148 pm) in the matrix-isolated linear molecule SiO
2 (O=Si=O), suggestive of the absence of a triple bond as in carbon monoxide. [3] However, the SiO triple bond has a calculated bond length of 150 pm and a bond energy of 794 kJ/mol, which are also very close to those reported for SiO. [16] In the carbon analogues the formal double bonds of carbon dioxide (116 pm) is also close to the triple bond length of carbon monoxide (112.8 pm); in light of this the observed bond length of SiO may be consistent with at least some triple-bond character in the diatomic molecule. The SiO double bond structure is, notably, an exception to Lewis' octet rule for molecules composed of the light main group elements, whereas the SiO triple bond satisfies this rule. That anomaly not withstanding, the observation that monomeric SiO is short-lived and that (SiO)'n' oligomers with 'n' = 2,3,4,5 are known, [17] all having closed ring structures in which the silicon atoms are connected through bridging oxygen atoms (i.e. each oxygen atom is singly bonded to two silicon atoms; no Si-Si bonds), suggests the Si=O double bond structure, with a hypovalent silicon atom, is likely for the monomer. [3]

Condensing molecular SiO in argon matrix together with fluorine, chlorine or carbonyl sulfide (COS), followed by irradiation with light, produces the planar molecules OSiF
2 (with Si-O distance 148 pm) and OSiCl
2 (Si-O 149 pm), and the linear molecule OSiS (Si-O 149 pm, Si-S 190 pm). [3]

Matrix-isolated molecular SiO reacts with oxygen atoms generated by microwave discharge to produce molecular SiO
2 which has a linear structure.

When metal atoms (such as Na, Al, Pd, Ag, and Au) are co-deposited with SiO, triatomic molecules are produced with linear (AlSiO and PdSiO), non-linear (AgSiO and AuSiO), and ring (NaSiO) structures. [3]

Solid (polymeric) form

Potter reported SiO solid as yellowish-brown in color and as being an electrical and thermal insulator. The solid burns in oxygen and decomposes water with the liberation of hydrogen. It dissolves in warm alkali hydroxides and in hydrofluoric acid. Even though Potter reported the heat of combustion of SiO to be 200 to 800 calories higher than that of an equilibrium mixture of Si and SiO2 (which could, arguably, be used as evidence that SiO is a unique chemical compound), [18] some studies characterized commercially available solid silicon monoxide materials as an inhomogeneous mixture of amorphous SiO2 and amorphous Si with some chemical bonding at the interface of the Si and SiO2 phases. [19] [20] Recent spectroscopic studies in a correlation with Potter's report suggest that commercially available solid silicon monoxide materials can not be considered as an inhomogeneous mixture of amorphous SiO2 and amorphous Si. [21]

Interstellar occurrence

Interstellar SiO was first reported in 1971 after detection in the giant molecular cloud Sgr B2. [22] SiO is used as a molecular tracer of shocked gas in protostellar outflows. [23]

Related Research Articles

<span class="mw-page-title-main">Alkane</span> Type of saturated hydrocarbon compound

In organic chemistry, an alkane, or paraffin, is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula CnH2n+2. The alkanes range in complexity from the simplest case of methane, where n = 1, to arbitrarily large and complex molecules, like pentacontane or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane.

<span class="mw-page-title-main">Carbon monoxide</span> Colourless, odourless, tasteless and toxic gas

Carbon monoxide is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest carbon oxide. In coordination complexes, the carbon monoxide ligand is called carbonyl. It is a key ingredient in many processes in industrial chemistry.

<span class="mw-page-title-main">Inorganic chemistry</span> Field of chemistry

Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.

<span class="mw-page-title-main">Oxide</span> Chemical compound where oxygen atoms are combined with atoms of other elements

An oxide is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– ion with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 that protects the foil from further oxidation.

<span class="mw-page-title-main">Silicon</span> Chemical element, symbol Si and atomic number 14

Silicon is a chemical element; it has 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 table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive.

<span class="mw-page-title-main">Silicon dioxide</span> Oxide of silicon

Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is abundant as it comprises several minerals and as a synthetic products. All forms are white or colorless, although impure samples can be colored.

<span class="mw-page-title-main">Silane</span> Chemical compound (SiH4)

Silane (Silicane) is an inorganic compound with chemical formula SiH4. It is a colourless, pyrophoric, toxic gas with a sharp, repulsive, pungent smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Silane with alkyl groups are effective water repellents for mineral surfaces such as concrete and masonry. Silanes with both organic and inorganic attachments are used as coupling agents. Silanes are commonly used to apply coatings to surfaces or as an adhesion promoter.

An oxyanion, or oxoanion, is an ion with the generic formula A
xOz−
y. Oxyanions are formed by a large majority of the chemical elements. The formulae of simple oxyanions are determined by the octet rule. The corresponding oxyacid of an oxyanion is the compound H
zA
xO
y. The structures of condensed oxyanions can be rationalized in terms of AOn polyhedral units with sharing of corners or edges between polyhedra. The oxyanions adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP) are important in biology.

<span class="mw-page-title-main">VSEPR theory</span> Model for predicting molecular geometry

Valence shell electron pair repulsion (VSEPR) theory, is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.

In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon (Si) and titanium (Ti). The process involves conversion of monomers into a colloidal solution (sol) that acts as the precursor for an integrated network of either discrete particles or network polymers. Typical precursors are metal alkoxides. Sol–gel process is used to produce ceramic nanoparticles.

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

Beryllium oxide (BeO), also known as beryllia, is an inorganic compound with the formula BeO. This colourless solid is a notable electrical insulator with a higher thermal conductivity than any other non-metal except diamond, and exceeds that of most metals. As an amorphous solid, beryllium oxide is white. Its high melting point leads to its use as a refractory material. It occurs in nature as the mineral bromellite. Historically and in materials science, beryllium oxide was called glucina or glucinium oxide, owing to its sweet taste.

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

Selenium dioxide is the chemical compound with the formula SeO2. This colorless solid is one of the most frequently encountered compounds of selenium.

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

The dioxygenyl(or dioxyl) ion, O+
2, is a rarely-encountered oxycation in which both oxygen atoms have a formal oxidation state of +1/2. It is formally derived from oxygen by the removal of an electron:

<span class="mw-page-title-main">Lower sulfur oxides</span>

The lower sulfur oxides are a group of inorganic compounds with the formula SmOn, where 2m > n. These species are often unstable and thus rarely encountered in everyday life. They are significant intermediates in the combustion of elemental sulfur. Some well characterized examples include sulfur monoxide (SO), its dimer S2O2, and a series of cyclic sulfur oxides, SnOx (x = 1, 2), based on cyclic Sn rings.

Aluminium(I) oxide is a compound of aluminium and oxygen with the chemical formula Al2O. It can be prepared by heating the stable oxide Al2O3 with elemental silicon at 1800 °C under vacuum.

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

Disiloxane has the chemical formula Si
2H
6O. It is the simplest known siloxane with hydrogen only R groups. The molecule contains six equivalent Si-H bonds and two equivalent Si-O bonds. Disiloxane exists as a colorless, pungent gas under standard conditions. However, it is generally safe for human use as evidence in its widespread use in cosmetics. It is also commonly known as disilyl ether, disilyl oxide, and perhydrodisiloxane

<span class="mw-page-title-main">Structure of liquids and glasses</span> Atomic-scale non-crystalline structure of liquids and glasses

The structure of liquids, glasses and other non-crystalline solids is characterized by the absence of long-range order which defines crystalline materials. Liquids and amorphous solids do, however, possess a rich and varied array of short to medium range order, which originates from chemical bonding and related interactions. Metallic glasses, for example, are typically well described by the dense random packing of hard spheres, whereas covalent systems, such as silicate glasses, have sparsely packed, strongly bound, tetrahedral network structures. These very different structures result in materials with very different physical properties and applications.

In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula AOmXn, where X is a halogen. Known oxohalides have fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I) in their molecules. The element A may be a main group element, a transition element, a rare earth element or an actinide. The term oxohalide, or oxyhalide, may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure.

Silicon carbonate is a crystalline substance formed under pressure from silica and carbon dioxide. The formula of the substance is SiCO4. To produce it silicalite is compressed with carbon dioxide at a pressure of 18 Gpa and a temperature around 740 K (467 °C; 872 °F). The silicon carbonate made this way has carbonate linked to silicon by way of oxygen in unidentate, bidentate, or bridged positions. However a stable crystal structure is not formed in these conditions. The phase produced is amorphous, but it has carbon in three-fold coordination, and silicon in six-fold coordination. When decompressed, not all carbon is released as carbon dioxide. If this really exists, the substance should be dynamically stable when reduced to atmospheric pressure.

A silicon–oxygen bond is a chemical bond between silicon and oxygen atoms that can be found in many inorganic and organic compounds. In a silicon–oxygen bond, electrons are shared unequally between the two atoms, with oxygen taking the larger share due to its greater electronegativity. This polarisation means Si–O bonds show characteristics of both covalent and ionic bonds. Compounds containing silicon–oxygen bonds include materials of major geological and industrial significance such as silica, silicate minerals and silicone polymers like polydimethylsiloxane.

References

  1. 1 2 Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, ISBN   0-12-352651-5
  2. ↑ Gibb, A.G.; Davis, C.J.; Moore, T.J.T., A survey of SiO 5 → 4 emission towards outflows from massive young stellar objects. Monthly Notices of the Royal Astronomical Society, 382, 3, 1213-1224. doi : 10.1111/j.1365-2966.2007.12455.x, arXiv : 0709.3088v1.
  3. 1 2 3 4 5 6 Peter Jutzi and Ulrich Schubert (2003) Silicon chemistry: from the atom to extended systems. Wiley-VCH ISBN   3-527-30647-1.
  4. ↑ HERTL, W.; PULTZ, W. W. (1967). "Disproportionation and Vaporization of Solid Silicon Monoxide". Journal of the American Ceramic Society. Wiley. 50 (7): 378–381. doi:10.1111/j.1151-2916.1967.tb15135.x. ISSN   0002-7820.
  5. 1 2 J. W. Mellor "A Comprehensive Treatise on Inorganic and Theoretical Chemistry" Vol VI, Longmans, Green and Co. (1947) p. 235.
  6. ↑ C. F. Maybery Amer. Chem. Journ. 9, 11, (1887).
  7. ↑ C. Winkler Ber. 23, (1890) p. 2652.
  8. ↑ U.S. Patent 182,082, July 26, 1905.
  9. ↑ E. F. Roeber H. C. Parmelee (Eds.) Electrochemical and Metallurgical Industry, Vol. 5 (1907) p. 442.
  10. ↑ "Handbook of Semiconductor Silicon Technology," W. C. O'Mara, R. B. Herring, L. P. Hunt, Noyes Publications (1990), p. 148
  11. ↑ Nuth III, Joseph A.; Ferguson, Frank T. (2006). "Silicates Do Nucleate in Oxygen-rich Circumstellar Outflows: New Vapor Pressure Data for SiO". The Astrophysical Journal. American Astronomical Society. 649 (2): 1178–1183. Bibcode:2006ApJ...649.1178N. doi: 10.1086/506264 . ISSN   0004-637X. S2CID   123656840.
  12. ↑ "High-Temperature Oxidation-Resistant Coatings ," National Academy of Sciences/National Academy of Engineering (1970), p. 40
  13. ↑ Charles A. (2004) Schacht Refractories handbook. CRC Press, ISBN   0-8247-5654-1.
  14. ↑ Han, Gilsoo; Sohn, Hong Yong (2005). "Kinetics of the Hydrogen Reduction of Silica Incorporating the Effect of Gas-Volume Change upon Reaction". Journal of the American Ceramic Society. Wiley. 88 (4): 882–888. doi:10.1111/j.1551-2916.2005.00144.x. ISSN   0002-7820.
  15. ↑ Gardner, Richard A. (1974). "The kinetics of silica reduction in hydrogen". Journal of Solid State Chemistry. Elsevier BV. 9 (4): 336–344. Bibcode:1974JSSCh...9..336G. doi:10.1016/0022-4596(74)90092-9. ISSN   0022-4596.
  16. 1 2 Inorganic Chemistry, Holleman-Wiberg, Academic Press (2001) p. 858.
  17. ↑ Chrystie, Robin S. M.; Janbazi, Hossein; Dreier, Thomas; Wiggers, Hartmut; Wlokas, Irenäus; Schulz, Christof (2019-01-01). "Comparative study of flame-based SiO2 nanoparticle synthesis from TMS and HMDSO: SiO-LIF concentration measurement and detailed simulation". Proceedings of the Combustion Institute. 37 (1): 1221–1229. doi:10.1016/j.proci.2018.07.024. ISSN   1540-7489. S2CID   139291303.
  18. ↑ J. W. Mellor "A Comprehensive Treatise on Inorganic and Theoretical Chemistry" Vol VI, Longmans, Green and Co. (1947) p. 234.
  19. ↑ Friede B., Jansen M. (1996) Some comments on so-called silicon monoxide. Journal of Non-Crystalline Solids, 204, 2, 202-203. doi : 10.1016/S0022-3093(96)00555-8.
  20. ↑ Schulmeister K. and Mader W. (2003) TEM investigation on the structure of amorphous silicon monoxide. Journal of Non-Crystalline Solids, 320, 1-3, 143-150. doi : 10.1016/S0022-3093(03)00029-2.
  21. ↑ Gunduz, D. C., Tankut, A., Sedani, S., Karaman, M. and Turan, R. (2015) Crystallization and phase separation mechanism of silicon oxide thin films fabricated via e-beam evaporation of silicon monoxide. Phys. Status Solidi C, 12: 1229–1235. doi : 10.1002/pssc.201510114.
  22. ↑ Wilson, R. W.; Penzias, A. A.; Jefferts, K. B.; Kutner, M.; Thaddeus, P. (1971). "Discovery of Interstellar Silicon Monoxide". The Astrophysical Journal. 167: L97. Bibcode:1971ApJ...167L..97W. doi: 10.1086/180769 . ISSN   0004-637X.
  23. ↑ Martin-Pintado, J.; Bachiller, R.; Fuente, A. (1992-02-01). "SIO Emission as a Tracer of Shocked Gas in Molecular Outflows". Astronomy and Astrophysics. 254: 315. Bibcode:1992A&A...254..315M. ISSN   0004-6361.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.