In this paper we report the assignments of infrared and Raman spectra
of N-chloroethylamine observed in the gas and solid phases. The normal
coordinate analyses were carried out by using ab initio force constan
ts. Two rotational isomers around the C-N axis were identified. The mo
st stable conformer is the one where the chlorine atom is trans to the
methyl group (T form) and the other is the one where the chlorine ato
m is gauche to the methyl group (G form) and the amino hydrogen is mos
t probably trans to the methyl group. The relative abundance of the T
form is 50% or more at room temperature.