Gas-phase spectroscopy of the unstable sulfur diisocyanate molecule S(NCO)2.
Sulfur diisocyanate is generated from a heterogeneous reaction of gaseous sulfur dichloride with silver cyanate and studied for the first time in the gas phase. Combined with quantum chemical calculations, the electronic structure is characterized by photoelectron spectroscopy (PES). Simultaneously, an investigation of the possible ionization and dissociation processes for the molecular cation is presented based on experimental soft ionization mass spectrometry. From the calculated bond-dissociation energies, the dissociation pathway is determined. S(NCO)2+ undergoes 1,3-sigmatropic rearrangement with a smaller barrier height (9.9 kcal mol(-1)) than the neutral counterpart. Thus, the 1,3-sigmatropic rearrangement is preferred for the molecular cation, and OCNCO+ and NS+ is produced by subsequent dissociation of the rearrangement product. The analysis agrees very well with the experimental mass spectrum.
Wang
Weigang
W
State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
Ge
Maofa
M
Yao
Li
L
Zeng
Xiaoqing
X
Sun
Zheng
Z
Wang
Dianxun
D