COD meaning in Chemistry ?

Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula C8H12; specifically [–(CH
2)
2–CH=CH–]2.

There are three configurational isomers with this structure, that differ by the arrangement of the four C–C single bonds adjacent to the double bonds. Each pair of single bonds can be on the same side (cis,Z) or on opposite sides (trans, E) of the double bond's plane; the three possibilities are denoted cis,cis, trans,trans, and cis,trans; or (Z,Z), (E,E), and (Z,E). (Because of overall symmetry, trans,cis is the same configuration as cis,trans.)

Generally abbreviated COD, the cis,cis isomer of this diene is a useful precursor to other organic compounds and serves as a ligand in organometallic chemistry. It is a colorless liquid with a strong odor. 1,5-Cyclooctadiene can be prepared by dimerization of butadiene in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005.