What is allene?(10 pts)

Allenes are a group of hydrocarbons. An allene is a hydrocarbon in which one atom of carbon is connected by C=C double bonds with two other atoms of carbon. (Allene is also the common name for the parent compound of this series, propadiene.) Such pair of C=C double bonds make allenes much more reactive than other alkenes. Besides, allenes can be chiral when C=C=C is attached to 4 difference alkyl groups or hydrogen atoms as C=C=C acts as a chiral centre (asymmetrical centre).

The following shows some examples of allenes:
H2C =C=CH2 propadiene
H2C =C=CHCH3 buta-1,2-diene
H3CCH=C=CHCH3 penta-2,3-diene
(H3C )2C =C=CHCH3 2-methylpenta-2,3-diene
........
etc.

2010-02-01 13:24:09 補充：
參考資料：老爺子 + Wikiopedia

allene咩來的
c=c好似係alkene wo