Chemical modeling for predicting the abundances of certain aldimines and
  amines in hot cores
  We consider six isomeric groups (CH3N, CH5N, C2H5N, C2H7N, C3H7N and C3H9N)
to review the presence of amines and aldimines within the interstellar medium
(ISM). Each of these groups contains at least one aldimine or amine.
Methanimine (CH2NH) from CH3N and methylamine (CH3NH2) from CH5N isomeric group
were detected a few decades ago. Recently, the presence of ethanimine (CH3CHNH)
from C2H5N isomeric group has been discovered in the ISM. This prompted us to
investigate the possibility of detecting any aldimine or amine from the very
next three isomeric groups in this sequence: C2H7N, C3H7N and C3H9N. We employ
high-level quantum chemical calculations to estimate accurate energies of all
the species. According to enthalpies of formation, optimized energies, and
expected intensity ratio, we found that ethylamine (precursor of glycine) from
C2H7N isomeric group, (1Z)-1-propanimine from C3H7N isomeric group, and
trimethylamine from C3H9N isomeric group are the most viable candidates for the
future astronomical detection. Based on our quantum chemical calculations and
from other approximations (from prevailing similar types of reactions), a
complete set of reaction pathways to the synthesis of ethylamine and
(1Z)-1-propanimine is prepared. Moreover, a large gas-grain chemical model is
employed to study the presence of these species in the ISM. Our modeling
results suggest that ethylamine and (1Z)-1-propanimine could efficiently be
formed in hot-core regions and could be observed with present astronomical
facilities. Radiative transfer modeling is also implemented to additionally aid
their discovery in interstellar space.
