A LASER-INDUCED FLUORESCENCE STUDY OF THE BIF AO-]X1O+ SYSTEM IN THE REGION 6550 TO 7400 ANGSTROM - ROTATIONAL ANALYSIS AND EVIDENCE FOR ANAO+ STATE POTENTIAL MAXIMUM()

Eighteen previously unobserved bands belonging to the BiF A O+-->X1Osystem have been identified in the region between 6550 and 7400 angstr om. Nine bands representing v'=27-29 and v''=40-45 have been rotationa lly analyzed, and the v'=27 and v'=29 states exhibit strong homogeneou s perturbations. These upper state levels are also observed to prediss ociate, providing evidence for an A O+ state potential maximum which h as been theoretically predicted. A limiting curve of dissociation sugg ests a rotationless potential maximum at 32 674+/-822 cm-1. This energ y must correspond to a potential maximum if it is to be reconciled wit h recent thermochemical measurements of the ground state dissociation energy, D0(0) = 3.76+/-0.13 eV. The new spectroscopic constants have b een included in a calculation of Rydberg-Klein-Rees potential curves f or both states. Franck-Condon factors calculated from these potentials are qualitatively consistent with the observed intensity distribution . Measured collision free radiative lifetimes are consistent with know n A O+ state lifetimes for nonpredissociated states and are found to b e shorter for predissociated states.