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Basic IUPAC Organic Nomenclature

Thioethers or sulfides

Nomenclature
Formula
3D structure
Functional class name = alkyl alkyl sulfide e.g. ethyl methyl sulfide

Substituent suffix = sulfide

Substituent prefix = alkylthio-   e.g. methylthioethane

Substitutive = -thio-

Structural unit :  thioethers contain R-S-R

"Simple" thioethers
  • Functional group is a simple thioether, therefore use alkyl alkyl sulfide
  • First substituent is C1 alkane therefore alkyl = methyl
  • Second substituent is C2 alkane therefore alkyl = ethyl

ethyl methyl sulfide

CH3CH2SCH3
  • Functional group is a simple thioether, therefore use alkyl alkyl sulfide
  • Both substituents are C1 alkane therefore alkyl = methyl
  • Since there are two alkyl groups, multipler = di
dimethyl sulfide
CH3SCH3


"Intermediate" thioethers
  • Hydrocarbon structure is an alkane therefore -ane
  • The longest continuous chain is C3 therefore root = prop
  • Substituent is C1 alkane therefore alkyl = methyl
  • The first point of difference rule requires numbering from the right as drawn to make the group locant 1-
1-methylthiopropane
CH3CH2CH2SCH3


"Complex" thioethers

  • Hydrocarbon structure is an alkane therefore -ane
  • Functional group is an thioether, therefore prefix = -thio-
  • The longest continuous chain (including the S)  is 5 therefore root = pent
  • Numbering from the left as drawn to make the thio group locant 2-
2-thiopentane

CH3SCH2CH2CH3


organic chemistry ©Dr. Ian Hunt, Department of Chemistry University of Calgary