Discovery of nitrogen formation after selective pumping of the 00 state of difluorodiazirine, F2CN2
摘要:
The vibrationless 0(0) state of the S1(A approximately 1B1) <-- S0(X approximately 1A1) transition in difluorodiazirine was excited with UV light by using a narrow-bandwidth (0.3 cm-1) pulsed dye laser. For the first time it was shown that dissociation occurs at this low energy and molecular nitrogen is a dissociation product. After photolysis, N2 was detected by 2 + 2 multiphoton ionization via the resonantly enhanced rotationally resolved A approximately 1-PI-g (upsilon' = 3) <-- X approximately 1-SIGMA-g+ (upsilon" = 0) transition. The dissociation quantum yield is only 2% after excitation of the electronic origin of the S1 state. From this result and our previous Doppler-free two-photon measurements of the same 0(0)0 band, we conclude that the dissociation proceeds via a coupling of the A approximately 1B1 state to the X approximately 1A1 electronic ground state.