The unstable species N-methylvinylamine was prepared by-the thermal de
composition of gaseous 2-methylaziridine in a flow system and its UV p
hotoelectron spectrum was recorded. The first two bands were observed
at 8.00 and 11.00 eV. The methyl substituent shows the effect of reduc
ing the degree of conjugation between the n(N) and pi(CC) orbitals, as
revealed by a comparison with the spectrum of the parent compound vin
ylamine.