STATE-SELECTED CHARGE-TRANSFER REACTION OF CO-A,UPSILON') WITH AR((X,UPSILON)

State-selected charge transfer reactions of CO+(X, v; A, v') with Ar h ave been studied for v = 0-9 and v' = 0-2 using the threshold electron secondary ion coincidence (TESICO) technique. In the endoergic CO+(X) + Ar --> Ar+ + CO reaction, the cross-section has been found to be gr eatly enhanced by vibrational excitation to v greater than or equal to 7. The cross-sections of the exoergic CO+(A) + Ar --> Ar+ + CO reacti on have been found to be generally large, having values of the order o f 10(-15) cm(2), and to show particular enhancement at v = 1. The expe rimental results have been discussed in conjuction with the potential energy surfaces calculated by G. Parlant, P. Archirel and E.A. Gislaso n (J. Chem. Phys., 92 (1990) 1211).