Triplet states of O-acyloximes were studied for the first time by means of
laser absorption spectroscopy. Energy transfer experiments showed that the
acyl moiety has no effect on the triplet energy, which depends only on the
ketone oxime part. It was observed that the difference between the tripler
energy of the parent ketone and that of the oxime varies, depending on the
oxime structure. This behaviour is explained on the basis of a non-vertical
character of the energy transfer reaction.