Scalar and vectorial properties in the photodissociation of tert-butyl nitrite from the S₁ and S₂ states

A detailed comparison between the dynamics of photodissociation of (CH ₃)₃CONO from its first two excited singlet states is presented. The fragmentation processes are studied by exciting the molecule at 365.8 and 351.8 nm [S₁(nπ*) ← S₀ transition] and at 250 nm [S₂(ππ*) ← S₀ transition] and probing the NO fragment by single photon laser induced fluorescence combined with polarization and sub-Doppler spectroscopy. The μ, v, and J vector correlations, Λ-doublet and spin-orbit populations, and the vibrational, rotational, and translational energy content of the NO fragment are determined. The scalar and vectorial properties point on different mechanisms of fragmentation from the S₁ and S₂ states, but both are highly selective. The findings of this study, especially those concerning the less studied S₂ state, can be utilized to predict the behavior of other alkyl nitrites and demonstrate the power of the techniques mentioned above in characterizing the dynamics of photodissociation, even for large molecules.