DINITROGEN SULFIDE, N2S, REVEALED BY PHOTOELECTRON-SPECTROSCOPY

The reactive dinitrogen sulfide molecule, N//2S, has been confirmed by He I photoelectron spectroscopic measurements as a major product of the thermal decomposition of 5-phenyl-1,2,3,4-thiatriazole. The adiabatic ionization energy of N//2S is 10. 55 eV, and its spectrum is characterized by two sharp ionization bands assigned as the ground **2 PI ( pi //s) and first excited **2 SIGMA ( sigma //N//N) states of the N//2S** plus ion. A broad band is tentatively assigned to the second excited **2 PI ( pi //N//N) ion state. Comparison with the spectrum of its stable analogue, OCS, indicates that the N-S bond is relatively weak so that the S atom effects only small perturbations of the sigma //g and pi //u molecular orbitals of N//2 within the linear N//2S molecule.