Isoprene

related topics
{acid, form, water}
{disease, patient, cell}
{specie, animal, plant}
{island, water, area}
{day, year, event}

−145.95 °C

34.067 °C

Isoprene (short for isoterpene), or 2-methyl-1,3-butadiene, is a common organic compound with the formula CH2=C(CH3)CH=CH2. Under standard conditions it is a colorless liquid. However, this compound is highly volatile because of its low boiling point.

Isoprene (C5H8) is the monomer of natural rubber and also a common structure motif to an immense variety of other naturally occurring compounds, collectively termed the isoprenoids. Molecular formula of isoprenoids are multiples of isoprene in the form of (C5H8)n, and this is termed the isoprene rule. The functional isoprene units in biological systems are dimethylallyl diphosphate (DMADP) and its isomer isopentenyl diphosphate (IDP).

The singular terms “isoprene” and “terpene” are synonymous whereas the plurals “isoprenes” or “terpenes” refer to terpenoids (isoprenoids).

Contents

Natural occurrences

Isoprene is produced and emitted by many species of trees into the atmosphere (major producers are oaks, poplars, eucalyptus and some legumes). The yearly production of isoprene emissions by vegetation is around 600 Tg, with half that coming from tropical broadleaf trees and the remainder coming from shrubs.[1] This is about equivalent to methane emission into the atmosphere and accounts for ~1/3 of all hydrocarbons released into the atmosphere. After release, isoprene is converted by free radicals (like the hydroxyl (OH) radical) and to a lesser extent by ozone [2] into various species, such as aldehydes, hydroperoxides, organic nitrates and epoxides, which mix into water droplets and help create aerosols and haze.[3][4] While most in the field acknowledges isoprene emission affect aerosol formation, whether isoprene increases or decreases aerosol formation is debated. A second major effect of isoprene on the atmosphere is that in presence of nitric oxides (NOx) it contributes to the formation of tropospheric (lower atmosphere) ozone, which is one of the leading air pollutants in many countries. Isoprene itself is normally not regarded as a pollutant, as it is one of the natural products from plants. Formation of tropospheric ozone is only possible in presence of high levels of NOx, which comes almost exclusively from industrial activities. In fact, isoprene can have the opposite effect and quench ozone formation under low levels of NOx.

Full article ▸

related documents
Americium
Extractive metallurgy
Cellulose
Ribosome
Pyridine
Eutectic point
Picric acid
Nucleotide
Primer (molecular biology)
Deoxyribose
Filtration
Radionuclide
Tartaric acid
Coke (fuel)
Hydrogen cyanide
Oxidation state
Fluorite
Kaolinite
Toluene
Coenzyme Q - cytochrome c reductase
Ethylene glycol
Proline
Protease
Californium
Ununtrium
Gallium
Cytochrome c oxidase
Indium
Green fluorescent protein
Guanine