Pentadienyl


In chemistry, pentadienyl refers to the organic radical, anion, or cation with the formula z, where z = 0, −1, +1, respectively.

Organometallic chemistry

In organometallic chemistry, the pentadienyl anion is a ligand, the acyclic analogue of the more common cyclopentadienyl. It is generated by deprotonation of pentadiene. A number of complexes are known, including the analogue of ferrocene, Fe2. Only few pentadienyl complexes feature C5H7 ligands. More common is the dimethyl analogue 2,4-Me2C5H5. Additionally, many pentadienyl ligands are cyclic, being derived from the addition of hydride to η6-arene complexes or hydride abstraction from cyclohexadiene complexes.
The first pentadienyl complex to be reported was derived from protonolysis of a complex of pentadienol:
Treatment of this cation with sodium borohydride gives the pentadiene complex:

Organic chemistry

In organic chemistry, the pentadienyl radical,, is of some significance as an especially stabilized radical. The radical is delocalized over five carbon centers. Consequently the C−H bond in the diene is especially weak. Fats derivatives containing this "doubly allylic" group are collectively called drying oils. They tend to polymerize in a useful way upon exposure to air.

Biochemistry

s are enzymes that generate prostanoids, including thromboxane and prostaglandins such as prostacyclin. Aspirin and ibuprofen exert their effects through inhibition of COX.
to generate a pentadienyl radical, initiating the COX cycle.