  The chemistry of complex organic molecules in interstellar dark clouds is
still highly uncertain in part because of the lack of constraining
observations. Orion is the closest massive star-forming region, and
observations making use of ALMA allow us to separate the emission regions of
various complex organic molecules (COMs) in both velocity and space. Orion also
benefits from an exceptional situation, in that it is the site of a powerful
explosive event that occurred 550 years ago. We show that the closely
surrounding Kleinmann-Low region has clearly been influenced by this explosion;
some molecular species have been pushed away from the densest parts while
others have remained in close proximity. This dynamical segregation reveals the
time dependence of the chemistry and, therefore allows us to better constrain
the formation sequence of COMs and other species, including deuterated
molecules.
