Radiative lifetimes, fluorescence quantum yields and photodissociation of the C2N2 (A1Σu−) and (B1Δu) states: evidence for sterically hindered, triplet mediated crossings to the (X1Σg+) ground state Original Research Article

C2N2 A1Σu−→X1Σg+ and B1Δu→X1Σg+ absorption, laser-induced fluorescence and CN photodissociation fragment spectra have been measured between 230 and 206 nm. Photophysical properties of individual vibrational levels of both electronically excited states are reported. Radiative lifetimes, quenching rates and fluorescence and dissociation quantum yields have been measured for the A1Σu− state. All vibrational bands of the B1Δu state are pre-dissociative with a 100% yield to CN fragments.