An electron spin echo and laser photolysis study of chemically induced electron spin orientation in the triplet ground state of diphenylmethylene

The electron spin in the triplet ground state of diphenylmethylene is found to be oriented predominantly in the plane perpendicular to the long molecular axis after the photo-dissociation reaction of diphenyldiazomethane. The spin selectivity of the intersystem crossing which occurs when the methylene relaxes to its ground state is suggested as the orientation mechanism. The combined spin echo and laser photolysis are shown to be very suitable for this kind of investigation.