The binding energy between NO and NO+

The photoionization efficiency curve of the nitric oxide dimer (NO)2 was obtained in the wavelength range from 1460 to 1210 Å (8.492–10.246 eV). The ionization potential of (NO)2 was found to be 8.746±0.015 eV. From this, the ionization potential of NO and the dissociation energy of (NO)2 (0.069±0.004 eV) obtained by Billingsley and Callear, the dissociation energy of NO(2Π, v′′=0) –NO+(1Σ+, v′=0) is deduced to be 0.59±0.02 eV. From the comparison of the structure of the photoion yield curve of NO and (NO)2 it is concluded that NO(2Π, v′′=0) –NO+(1Σ+, v′) is bound when NO+(X1Σ+) is in the v′=0 or 1 vibrational state. This conclusion is in agreement with the dissociation energy of (NO)+2 obtained.