Photodissociation of ICl molecules oriented in an electric field. Direct determination of the sign of the dipole moment

We have used the ‘brute force’ technique of Loesch to orient strongly a molecular beam of ICl, and we have measured directly the orientation by a photodissociation experiment. This experiment gives also a direct access to the sign of the dipole moment of ICl in its X1Σ+ state, which is found to be I+Cl−.