An ab initio quantum chemical study of the five possible isomers, tran
s-and cis-conformations of nitrosoethylene, 4H-1,2-oxazete, 2H-1 aziri
ne 1-oxide and acetonitrile oxide, of C2H3NO is reported. Molecular ge
ometries and energies have been obtained at the Hartree-Fock and secon
d-order Moller-Plesset levels of theory. It is important to note that
in both the levels of theory, acetonitrile oxide is found to be the mo
st stable isomer among all the five structures. Atomic charges, throug
h Mulliken and natural population analysis schemes, dipole moments, en
tropies and rotational constants have been calculated using the above-
mentioned levels. Various basis sets, 3-21G, 6-31G, 6-31G* and 6-311G
, have been used at the HF level of calculation and 6-31G* basis set
has been utilized at the MP2 level of calculation. Finally, the vibrat
ional spectra of all the five structures have been obtained using the
HF/3-21G, HF/6-31G* and HF/6-311G* levels. An imaginary frequency has
been found for the cis conformer of the nitrosoethylene molecule at b
oth the HF/6-31G* and HF/6-311G* levels. (C) 1998 Elsevier Science B.
V.