Hexasulfur is an
inorganic
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''.
Inor ...
chemical
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combin ...
with the chemical formula . This allotrope was first prepared by M. R. Engel in 1891 by treating
thiosulfate
Thiosulfate ( IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, ...
with HCl.
''Cyclo''- is orange-red and forms a
rhombohedral
In geometry, a rhombohedron (also called a rhombic hexahedron or, inaccurately, a rhomboid) is a special case of a parallelepiped in which all six faces are congruent rhombus, rhombi. It can be used to define the rhombohedral lattice system, a Ho ...
crystal.
It is called ρ-sulfur, ε-sulfur, Engel's sulfur and Aten's sulfur.
Another method of preparation involves the reaction of a
polysulfane
A polysulfane is a chemical compound of formula , where ''n'' > 1 (although disulfane () is sometimes excluded). Compounds containing 2 – 8 sulfur atoms have been isolated, longer chain compounds have been detected, but only in solution.R. Steud ...
with
sulfur monochloride:
[
: (dilute solution in ]diethyl ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...
)
Nomenclature
The name hexasulfur is the most commonly used and preferred IUPAC name
In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among all possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choo ...
and is constructed according to the compositional nomenclature, and cyclohexasulfane. It is also the final member of the thiane heterocyclic series, where every carbon atom is substituted with a sulfur atom, thus the systematic name hexathiane, a valid IUPAC
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...
name, is constructed according to the substitutive nomenclature. Another valid IUPAC systematic name ''cyclo''-hexasulfur is constructed according to the additive nomenclature.
Structure
This chemical consists of rings of 6 sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
atoms. It is thus a simple cyclosulfane and an allotrope of sulfur. Hexasulfur adopts a chair configuration
Cyclohexane conformations are any of several three-dimensional shapes adopted by cyclohexane. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide r ...
similar to that of cyclohexane
Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexan ...
, with bond angles of 102.2°. The sulfur atoms are equivalent.[
]
References
{{Reflist
Six-membered rings
Allotropes of sulfur