The molecule, known as trisulfur, sulfur trimer, thiozone, or triatomic sulfur, is a cherry-red
allotrope of sulfur
The element sulfur exists as many allotropes. In number of allotropes, sulfur is second only to carbon. Greenwood, 652 In addition to the allotropes, each allotrope often exists in polymorphs (different crystal structures of the same covalently ...
. It comprises about 10% of vaporised sulfur at and . It has been observed at cryogenic temperatures as a solid. Under ordinary conditions it converts to
cyclooctasulfur.
:8 S
3 → 3 S
8
Structure and bonding
In terms of structure and bonding and
ozone
Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...
() are similar. Both adopt
bent structures and are
diamagnetic
Diamagnetic materials are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted ...
. Although represented with S=S
double bonds
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 ...
, the bonding situation is more complex.
The S–S distances are equivalent and are , and with an angle at the central atom of . However, cyclic , where the sulfur atoms are arranged in an equilateral triangle with three single bonds (similar to
cyclic ozone
Cyclic ozone is a theoretically predicted form of ozone. Like ordinary ozone (O3), it would have three oxygen atoms. It would differ from ordinary ozone in how those three oxygen atoms are arranged. In ordinary ozone, the atoms are arranged in ...
and
cyclopropane
Cyclopropane is the cycloalkane with the molecular formula (CH2)3, consisting of three methylene groups (CH2) linked to each other to form a ring. The small size of the ring creates substantial ring strain in the structure. Cyclopropane itself ...
), is calculated to be lower in energy than the bent structure experimentally observed.
The name thiozone was invented by
Hugo Erdmann
Hugo Wilhelm Traugott Erdmann (8 May 1862 – 25 June 1910) was the German chemist who discovered, together with his doctoral advisor Jacob Volhard, the Volhard-Erdmann cyclization. In 1898 he was the first who coined the term ''noble gas'' (the ...
in 1908 who hypothesized that comprises a large proportion of liquid sulfur. However its existence was unproven until the experiments of J. Berkowitz in 1964.
[ Using ]mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is use ...
, he showed that sulfur vapour contains the molecule. Above is the second most common molecule after in gaseous sulfur. In liquid sulfur the molecule is not common until the temperature is high, such as . However, small molecules like this contribute to most of the reactivity of liquid sulfur.[ has an absorption peak of (violet) with a tail extending into blue light.][
can also be generated by ]photolysis
Photodissociation, photolysis, photodecomposition, or photofragmentation is a chemical reaction in which molecules of a chemical compound are broken down by photons. It is defined as the interaction of one or more photons with one target molecule. ...
of embedded in a glass or matrix of solid noble gas
The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemi ...
.[
]
Natural occurrence
occurs naturally on Io in volcanic emissions. is also likely to appear in the atmosphere of Venus at heights of , where it is in thermal equilibrium with and . The reddish colour of Venus' atmosphere at lower levels is likely to be due to .
Reactions
reacts with carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
to make carbonyl sulfide
Carbonyl sulfide is the chemical compound with the linear formula OCS. It is a colorless flammable gas with an unpleasant odor. It is a linear molecule consisting of a carbonyl group double bonded to a sulfur atom. Carbonyl sulfide can be consi ...
and .
Formation of compounds with a defined number of sulfur atoms is possible:
: + → (cyclic)
Radical anion
Although is elusive under ordinary conditions, the radical anion
In organic chemistry, a radical anion is a free radical species that carries a negative charge. Radical anions are encountered in organic chemistry as reduced derivatives of polycyclic aromatic compounds, e.g. sodium naphthenide. An example of ...
is abundant. It exhibits an intense blue colour. The anion is sometimes called thiozonide, by analogy with the ozonide
Ozonide is the polyatomic anion . Cyclic organic compounds formed by the addition of ozone () to an alkene are also called ozonides.
Ionic ozonides
Inorganic ozonides are dark red salts. The anion has the bent shape of the ozone molecule.
Ino ...
anion, , to which it is valence isoelectronic
Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in th ...
. The gemstone lapis lazuli
Lapis lazuli (; ), or lapis for short, is a deep-blue metamorphic rock used as a semi-precious stone that has been prized since antiquity for its intense color.
As early as the 7th millennium BC, lapis lazuli was mined in the Sar-i Sang mines, ...
and the mineral lazurite
Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula . It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usually ...
(from which the pigment ultramarine
Ultramarine is a deep blue color pigment which was originally made by grinding lapis lazuli into a powder. The name comes from the Latin ''ultramarinus'', literally 'beyond the sea', because the pigment was imported into Europe from mines in Afgh ...
is derived) contain . International Klein Blue
International Klein Blue (IKB) is a deep blue hue first mixed by the French artist Yves Klein. IKB's visual impact comes from its heavy reliance on ultramarine, as well as Klein's often thick and textured application of paint to canvas.
Histo ...
, developed by Yves Klein
Yves Klein (; 28 April 1928 – 6 June 1962) was a French artist and an important figure in post-war European art. He was a leading member of the French artistic movement of Nouveau réalisme founded in 1960 by art critic Pierre Restany. Klein w ...
, also contains the radical anion. The blue colour is due to the C2A2 transition to the X2B1 electronic state in the ion,[ causing a strong absorption band at 610– or (in the orange region of the visible spectrum).][ The ]Raman frequency
Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman sp ...
is and another infrared absorption is at .[
The ion has been shown to be stable in aqueous solution under a pressure of , and is expected to occur naturally at depth in the earth's crust where subduction or high pressure metamorphism occurs. This ion is probably important in movement of copper and gold in ]hydrothermal fluid
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...
s.
Lithium hexasulfide (which contains , another polysulfide radical anion) with tetramethylenediamine solvation dissociates acetone and related donor solvents to .
The radical anion was also made by reducing gaseous sulfur with in a matrix. The material is strongly blue-coloured when dry and changes colour to green and yellow in the presence of trace amounts of water. Another way to make it is with polysulfide
Polysulfides are a class of chemical compounds containing chains of sulfur atoms. There are two main classes of polysulfides: inorganic and organic. Among the inorganic polysulfides, there are ones which contain anions, which have the general formu ...
dissolved in hexamethylphosphoramide
Hexamethylphosphoramide, often abbreviated HMPA, is a phosphoramide (an amide of phosphoric acid) with the formula This colorless liquid is a useful reagent in organic synthesis.
Structure and reactivity
HMPA is the oxide of the highly basic t ...
where it gives a blue colour.
Other methods of production of include reacting sulfur with slightly dampened magnesium oxide
Magnesium oxide ( Mg O), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...
.
Raman spectroscopy
Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman sp ...
can be used to identify , and it can be used non-destructively in paintings. The bands are for symmetric stretch, for asymmetric stretch, and for bending. Natural materials can also contain which has an optical absorption at and Raman band at .[
]
Trisulfide ion
The trisulfide ion, is part of the polysulfide
Polysulfides are a class of chemical compounds containing chains of sulfur atoms. There are two main classes of polysulfides: inorganic and organic. Among the inorganic polysulfides, there are ones which contain anions, which have the general formu ...
series. The sulfur chain is bent at an angle of 107.88°.[ has a S–S bond length of .][ The bonds are single. It is ]isoelectronic
Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in the ...
to sulfur dichloride
Sulfur dichloride is the chemical compound with the formula . This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to organosulfur compounds. It is a highly corrosive and toxic substance, ...
.
References
External links
*{{Commonscatinline
Allotropes of sulfur
Homonuclear triatomic molecules
Gases with color