Abstract
We report results from experiments with the quinoline-O-2 complex, which was photodissociated using light near 312nm. Photodissociationresulted in formation of the lowest excited state of oxygen, O-2 a (1)Delta(g), which we detected usingresonance enhanced multiphoton ionization and velocity map ion imaging.The O-2 (+) ion image allowed for a determinationof the center-of-mass translational energy distribution, P(E (T)), following complex dissociation.We also report results of electronic structure calculations for thequinoline singlet ground state and lowest energy triplet state. Fromthe CCSD/aug-cc-pVDZ//(U)MP2/cc-pVDZ calculations, we determined thelowest energy triplet state to have pi pi* electronic characterand to be 2.69 eV above the ground state. We also used electronicstructure calculations to determine the geometry and binding energyfor several quinoline-O-2 complexes. The calculations indicatedthat the most strongly bound complex has a well depth of about 0.11eV and places the O-2 moiety above and approximately parallelto the quinoline ring system. By comparing the experimental P(E (T)) with the energy for thesinglet ground state and the lowest energy triplet state, we concludedthat the quinoline product was formed in the lowest energy tripletstate. Finally, we found the experimental P(E (T)) to be in agreement with a Prior translationalenergy distribution, which suggests a statistical dissociation forthe complex.