Guided ion beam and theoretical studies of the bond energy of SmS.

Previous work has shown that atomic samarium cations react with carbonyl sulfide to form SmS + CO in an exothermic and barrierless process. To characterize this reaction further, the bond energy of SmS is determined in the present study using guided ion beam tandem mass spectrometry. Reactions of SmS with Xe, CO, and O are examined. Results for collision-induced dissociation processes with all three molecules along with the endothermicity of the SmS + CO → Sm + COS exchange reaction are combined to yield D(Sm-S) = 3.37 ± 0.20 eV. The CO and O reactions also yield a SmSO product, with measured endothermicities that indicate D(SSm-O) = 3.73 ± 0.16 eV and D(OSm-S) = 1.38 ± 0.27 eV. The SmS bond energy is compared with theoretical values characterized at several levels of theory, including CCSD(T) complete basis set extrapolations using all-electron basis sets. Multireference configuration interaction calculations with explicit spin-orbit calculations along with composite thermochemistry using the Feller-Peterson-Dixon method and all-electron basis sets were also explored for SmS, and for comparison, SmO, SmO, and EuO.