Direct Measurement of the N2+C State Predissociation Probability

The lifetimes of the vibrational ν = 1-5 levels of the N2+C state have been directly measured at high resolution using the High Frequency Deflection technique. For the ν = 2 level, a radiative lifetime τ = 78.9 ± 3.0 ns is obtained, while the lifetimes drop sharply to a constant value of 4-5 ns for the ν ⩾ 3 levels. Since the ν ⩾ 3 levels are all above the lowest dissociation limit, the measurements confirm that these levels are predissociated and at a rate of about 2 × 108s-1. The lifetime variation suggests that the predissociation mainly takes place through vibrational coupling with theBstate.