Selected ion flow drift tube study of the formation and dissociation of CO~+.N_2 ions in nitrogen buffer gas: the CO~+.N_2 bond energy

摘要

Efficient vibrational quenching of CO~+ (ν = 1) by N_2 led to the deduction of an unexpectedly strong attractive potential between CO~+ and N_2. This was subsequently confirmed by ab initio quantal calculations of the CO~+.N_2 bond strength. The bond energy of CO~+.N_2 has now been determined in a selected ion flow drift tube, by measuring collisional destruction and formation of CO~+.N_2. The bond energy is found to be 0.7 ± 0.2 eV. This is sufficiently large to rationalize the fast vibrational quenching but somewhat less than an ab initio value. The large value of D(CO~+.N_2) can unambiguously be explained by resonance interaction between CO~+.N_2 and the charge-transfer CO.N_2~+ states.