|Molar mass||94.11 g/mol|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)|
Oxepin is an oxygen-containing heterocycle consisting of a seven-membered ring with three double bonds. It exists as an equilibrium mixture with benzene oxide. The oxepin-benzene oxide system has fluctuating bonds in which the equilibrium can be shifted to one extreme or the other by suitable substituents.