Resonant two-photon ionization spectroscopy of jet-cooled OsN: 520-418 nm

The optical transitions of supersonically cooled OsN have been investigated in the range from 19 200 to 23 900 cm(-1) using resonant two-photon ionization spectroscopy. More than 20 vibronic bands were observed, 17 of which were rotationally resolved and analyzed. The ground state is confirmed to be (2)Delta(5/2), deriving from the 1 sigma(2) 2 sigma(2) 1 pi(4) 1 delta(3) 3 sigma(2) electronic configuration. The X-2 Delta(5/2) ground state rotational constant for (OsN)-Os-192-N-14 was found to be B-0 = 0.491921(34) cm(-1), giving r(0) = 1.62042(6) angstrom (1 sigma error limits). The observed bands were grouped into three band systems with Omega' = 7/2 and four with Omega' = 3/2, corresponding to the three 2(1)7,2 and four (2)Pi(3/2) states expected from the 1 sigma(2) 2 sigma(2) 1 pi(4) 1 delta(3) 3 sigma(1) 2 pi(1) and 1 sigma(2) 2 sigma(2) 1 pi(4) 1 delta(2) 3 sigma(2) 2 pi(1) electronic configurations. In addition, two interacting upper states with Omega' = 5/2 were observed, one of which is thought to correspond to a 1 sigma(2) 2 sigma(2) 1 pi(3) 1 delta(3) 3 sigma(2) 2 pi(1), (2)Delta(5/2) state. Spectroscopic constants are reported for all of the observed states, and comparisons to related molecules are made. The ionization energy of OsN is estimated as IE(OsN) = 8.80 +/- 0.06 eV. (C) 2011 American Institute of Physics. [doi:10.1063/1.3633694]