Rotationally resolved photoelectron spectroscopy of hot N-2 formed in the photofragmentation of N2O

The photoionization dynamics of rotationally hot molecular nitrogen are stu died employing resonance enhanced multiphoton ionization in combination wit h photoelectron spectroscopy. Photodissociation of N2O at similar to 203 nm results in highly rotationally excited N-2 fragments in X (1)Sigma (+)(g)( N",v"=0,1) states and O atoms in the excited D-1(2) state. Photoelectron de tection of the rotationally hot N-2 states is performed by a two-photon exc itation to the lowest a" (1)Sigma (+)(g) Rydberg state followed by one-phot on ionization. The large number of observed rotational levels, from N'=49 u p to N'=94, results in improved rotational parameters for a" (1)Sigma (+)(g ) (v'=0). In addition, experimental and theoretical rotationally resolved p hotoelectron spectra of the a" (1)Sigma (+)(g)(v(')=0,1;N') state are prese nted. In these spectra only DeltaN=N+-N'=even transitions are observed, wit h a dominant DeltaN=0 peak and rather weak DeltaN=+/-2 peaks. The one-photo n ionization is dominated by ejection of electrons in p and f partial waves . The agreement between experimental and calculated spectra is excellent. ( C) 2001 American Institute of Physics.