Thiirane

Thiirane, more commonly known as ethylene sulfide, is the cyclic chemical compound with the formula C₂H₄S.^[2] It is the smallest sulfur-containing heterocycle and the simplest episulfide. Like many organosulfur compounds, this species has a highly unpleasant odour. Thiirane is also used to describe any derivative of the parent ethylene sulfide.

Thiirane

Skeletal formula of thiirane Spacefill model of thiirane
Ball-and-stick model of thiirane
Names
Preferred IUPAC name Thiirane
Systematic IUPAC name Thiacyclopropane
Other names 2,3-Dihydrothiirene[1] Ethylene sulfide[1]
Identifiers
CAS Number	420-12-2 Y
3D model (JSmol)	Interactive image
Beilstein Reference	102379
ChEBI	CHEBI:30977 Y
ChemSpider	9481 Y
ECHA InfoCard	100.006.359
EC Number	206-993-9
Gmelin Reference	1278
KEGG	C19419 N
MeSH	ethylene+sulfide
PubChem CID	9865
RTECS number	KX3500000
UNII	A2W5165740 Y
UN number	1992
CompTox Dashboard (EPA)	DTXSID3049411
InChI InChI=1S/C2H4S/c1-2-3-1/h1-2H2 Y Key: VOVUARRWDCVURC-UHFFFAOYSA-N Y
SMILES C1CS1
Properties
Chemical formula	C2H4S
Molar mass	60.11 g·mol−1
Appearance	Pale, yellow liquid
Density	1.01 g cm−3
Melting point	−109 °C (−164 °F; 164 K)
Boiling point	56 °C; 133 °F; 329 K
Vapor pressure	28.6 kPa (at 20 °C)
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	51–53 kJ mol−1
Std enthalpy of combustion (ΔcH⦵298)	−2.0126 MJ mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H318, H331
Precautionary statements	P210, P261, P280, P301+P310, P305+P351+P338, P311
NFPA 704 (fire diamond)	3 4 2
Flash point	10 °C (50 °F; 283 K)
Related compounds
Related heterocycles	Ethylene oxide Aziridine Borirane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

For the class of compounds known as thiiranes, see Episulfide.

Structure and properties

According to electron diffraction, 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°.^[3] The microwave and infrared spectra were studied experimentally and computationally.^[4]

Preparation and reactions

It can be prepared by the reaction of ethylene carbonate and KSCN.^[5] For this purpose the KSCN is first melted under vacuum to remove water.

KSCN + C₂H₄O₂CO → KOCN + C₂H₄S + CO₂

Ethylenesulfide adds to amines to afford 2-mercaptoethylamines,^[6] which are good chelating ligands.

C₂H₄S + R₂NH → R₂NCH₂CH₂SH

This process is often called mercaptoethylation.^[7]

Oxidation of thiirane with periodate gives ethylene episulfoxide.