Jump to searchIsoprene Full structural formula of isoprene Skeletal formula of isoprene Ball-and-stick model of isoprene Space-filling model of isoprene Names Preferred IUPAC name 2-Methylbuta-1,3-diene Other names 2-Methyl-1,3-butadieneIsoprene Identifiers CAS Number 78-79-5 ☑ 3D model (JSmol) Interactive image ChEBI CHEBI:35194 ☑ ChemSpider 6309 ☑ ECHA InfoCard 100.001.040 KEGG C16521 ☑ PubChem CID 6557 UNII 0A62964IBU ☑ CompTox Dashboard (EPA) DTXSID2020761 Edit this at Wikidata InChI[show]☑☑ SMILES[show] Properties Chemical formula C5H8 Molar mass 68.12 g/mol Density 0.681 g/cm3 Melting point −143.95 °C (−227.11 °F; 129.20 K) Boiling point 34.067 °C (93.321 °F; 307.217 K) Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). ☑ verify (what is ☑☒ ?) Infobox references Isoprene, or 2-methyl-1,3-butadiene, is a common organic compound with the formula CH2=C(CH3)−CH=CH2. In its pure form it is a colorless volatile liquid. Isoprene is produced by many plants and animals[1] (including humans) and its polymers are the main component of natural rubber. C. G. Williams named the compound in 1860 after obtaining it from thermal decomposition (pyrolysis) of natural rubber; he correctly deduced the empirical formula C5H8.[2][3]