In organic chemistry, pentadiene is any hydrocarbon with an open chain of five carbons, connected by two single bonds and two double bonds. All those compounds have the same molecular formula C5H8. The inventory of pentadienes include:
- 1,2-pentadiene, or ethyl allene, H2C=C=CH−CH2−CH3.[1]
- 1,3-pentadiene, H2C=CH−CH=CH−CH3 with two isomers:[2][3]
- cis-1,3-pentadiene.
- trans-1,3-pentadiene, also known as piperylene.
- 1,4-pentadiene, H2C=CH−CH2−CH=CH2.[4]
- 2,3-pentadiene, H3C−CH=C=CH−CH3, with two enantiomers (R and S).[5]
Well known derivatives containing pentadiene groups include hexadienes, cyclopentadiene, and especially three fatty acids linoleic acid, α-linolenic acid, and arachidonic acid as well as their triglycerides (fats).
- ^ James R. Durig, Stephen Bell, Gamil A. Guirgis (1996): "Infrared and Raman spectra, conformational stability, ab initio calculations and vibrational assignment for 1,2-pentadiene (ethyl allene)". Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, volume 52, issue 14, pages 1843-1859.doi:10.1016/S0584-8539(96)01740-0
- ^ Aldo Priola, Sebastiano Cesca, Giuseppe Ferraris, and Mario Bruzzone (1975): "Relative reactivity of cis‐ and trans‐1,3‐pentadiene in the cationic copolymerization with isobutene". Die Makromolekulare Chemie, volume 176, issue 7, pages 1969-1981. doi:10.1002/macp.1975.021760707
- ^ S. Boue and Rangaswamy Srinivasan (1970): "Differences in reactivity between excited states of cis- and trans-1,3-pentadiene". Journal of the American Chemical Association, volume 92, issue 10, pages 3226–3227. doi:10.1021/ja00713a074
- ^ Paul N. Kogerman (1930): "Synthesis of 1,4-pentadiene". Journal of the American Chemical Association, volume 52, issue 12, pages 5060–5065. doi:10.1021/ja01375a064
- ^ Kenneth B. Wiberg, Yi-gui Wang, Shaun M. Wilson, Patrick H. Vaccaro, William L. Jorgensen, T. Daniel Crawford, Micah L. Abrams, James R. Cheeseman, and Mark Luderer (2008): "Optical Rotatory Dispersion of 2,3-Hexadiene and 2,3-Pentadiene". Journal of Physical Chemistry A J. Phys. Chem. A , 112, 2415-2422. doi:10.1021/jp076572o