Ethylene oxide (c-C2H4O) was initially detected in 1997 by
Dickens et al. Unlike most known astromolecules,
it has a ring structure. In fact, three-membered rings are rare even in terrestrial chemistry due to the amount
of strain involved. Ethylene oxide (or EtO) is an isomer of two more stable molecules,
acetaldehyde (CH3CHO) and
vinyl alcohol (CH2CHOH).
EtO is an epoxide
similar to other ethers but particularly reactive.
Like many astromolecules, EtO was identified in the interstellar medium by
means of its characteristic rotational spectrum, which gives rise to transitions in the