Thiirane, more commonly known as ethylene sulfide, is the cyclic
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the formula C
2H
4S. It is the smallest sulfur-containing
heterocycle
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different chemical element, elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis ...
and the simplest
episulfide
In organic chemistry, episulfides are a class of organic compounds that contain a saturated, heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiira ...
. Like many organosulfur compounds, this species has a highly unpleasant odour. Thiirane is also used to describe any derivative of the parent ethylene sulfide.
Structure
According to
electron diffraction
Electron diffraction refers to the bending of electron beams around atomic structures. This behaviour, typical for waves, is applicable to electrons due to the wave–particle duality stating that electrons behave as both particles and waves. Si ...
, the C-C and C-S distances in ethylene sulfide are respectively 1.473 and 1.811 Å. The C-C-S and C-S-C angles are respectively 66.0 and 48.0°.
Preparation and reactions
It can be prepared by the reaction of
ethylene carbonate
Ethylene carbonate (sometimes abbreviated EC) is the organic compound with the formula (CH2O)2CO. It is classified as the Cyclic compound, cyclic carbonate ester of ethylene glycol and carbonic acid. At room temperature (25 °C) ethylene car ...
and
KSCN. For this purpose the KSCN is first melted under vacuum to remove water.
:KSCN + C
2H
4O
2CO → KOCN + C
2H
4S + CO
2
Ethylenesulfide adds to amines to afford 2-mercaptoethylamines, which are good chelating ligands.
:C
2H
4S + R
2NH → R
2NCH
2CH
2SH
This process is often called mercaptoethylation.
Oxidation of thiirane with
periodate
Periodate is an anion composed of iodine and oxygen. It is one of a number of oxyanions of iodine and is the highest in the series, with iodine existing in oxidation state +7. Unlike other perhalogenates, such as perchlorate, it can exist in two ...
gives
ethylene episulfoxide
Ethylene episulfoxide is the organosulfur compound with the formula C2H4SO. A colorless liquid, it is one of the simplest sulfoxides. Because it is a strained ring, ethylene sulfoxide is a highly reactive molecule, decomposing thermally to sulfur ...
.
References
{{sulfur compounds
Episulfides