Click on the graph to display the various bonding and antibonding molecular orbitals and energies. Use Surfaces from the Jmol popup menu to display other molecular orbitals for each polyene.

• All the molecular orbitals for ethylene(ethene), 1,3-butadiene, 1,3,5-hexatriene, and 1,3,5,7-octatetraene are available.
• Note the increasing number of nodes as the conjugated chain increases
• Addition of successive conjugated double bonds progressively narrows the gap between HOMO and LUMO
• Thus longer wavelength (lower energy) radiation required for the chromophore transition