CHARGE-TRANSFER REACTION OF N-14,N-15(+)(P-3(J))+N-2((1)SIGMA(G)(+)) FROM THERMAL TO 100-EV - CROSSED-BEAM AND SCATTERING-CELL GUIDED-ION BEAM EXPERIMENTS

We have studied the charge-transfer reaction of ground-state N+(P-3(j)) ions with N-2((1) Sigma(g)(+)) from thermal to 40 to 100 eV in the center-of-mass frame with the Utah guided-ion beam mass spectrometer and the Trento crossed-beam guided-ion beam experiment. Although the formation of N-2(+)(X(2) Sigma(g)(+)) is endothermic by only 1.043 eV, the charge-transfer process to yield N-2(+) is not observed until approximately 2.8 eV. Studies using isotopically labeled N-15(+) ions demonstrate that electron-and atom-transfer channels start at the same energy and have similar energy dependencies until about 6 eV, a result that implies a symmetric but acyclic N-3(+) intermediate. We discuss the mechanism for this reaction by means of state correlation diagrams that demonstrate that the charge-transfer reaction must involve strong nonadiabatic effects.