Study on the Free Radicals and Abnormal Photoreaction Behaviour of ο-Substituted Nitrobenzaldehydes

I Introduction The abnormal photoreaction property of o-nitrobenzaldehyde, which is one of the standard scintillators and the reference material in quantum etficient measurement of photochernistry, has been paid much attention to. Up to now, however, its photoreaction mechanism has not been cleared yet. Tech et al observed the ESR spectrum produced in the photochemical reaction of alcohol solution of o-nitrobenzaldehyde, but they did not probe