The monoenergetic vibrational predissociation of expansion cooled NCNO: Nascent CN(V,R) distributions at excess energies 0–5000 cm−1

We report detailed vibration, rotation distributions for nascent CN(X 2∑+), following the one‐photon photodissociation of expansion cooled NCNO via π*←n excitation throughout the region 450–585 nm. At the observed threshold for dissociation (585.3 nm), >90% of the CN product is in v″=0, N″=0, with the remainder in N″=1, corresponding to 〈Erot〉 <0.4 cm−1. CN(X 2∑+, v″=0) rotational distributions are obtained at many photolysis wavelengths and rotational levels are observed up to, but never above, the limit imposed by energy conservation: [B″vN″(N″+1)]internal conversion to the ground state surface. With Ep−D0(v″) ...