Photodissociation of MgC60+ complexes generated and stored in a linear ion trap

This Letter presents a general technique for the determination of absolute photodissociation cross-sections of ionic molecular complexes in the gas phase. Experiments on MgC60+ complexes were used to demonstrate the effectiveness of this approach. The complexes were generated collisionally inside a linear ion trap, and stored for periods of 30 s or longer during which laser induced photodissociation measurements were carried out. The dissociation rates were determined using either a mass spectrometric or a fluorescence technique, and were found to have a linear dependence on incident laser powers up to 50 mW (∼ 300 W/cm2 intensity). The total photodissociation cross-sections increase from 10−18 to 10−16 cm2 for photon energies ranging from 1.96 to 4.46 eV.