The kinetic-energy dependence of SO2 activated by Os+ was studied by guided ion beam tandem mass spectrometry. Species observed in endothermic reactions were OsO+, OsO2+ or OsS+, and OOsS+. The kinetic energy-dependent cross sections were modeled to yield 0 K bond dissociation energies (BDEs) of 5.01 +/- 0.06 eV (Os+-O), 5.15 +/- 0.07 eV (Os+-O-2), 4.50 +/- 0.17 eV (Os+-S), and 4.22 +/- 0.11 eV (Os+-SO). Among these BDE values, the values for OsO+ and OsO2+ agree with literature values and those for OsS+, and OsSO+, are novel measurements. Theoretical calculations were performed at a B3LYP/def2-TZVPPD level for all products, and additional calculations were performed for OsS+, OsO2+, and OsSO+ using the CCSD(T) level of theory, extrapolated to the complete basis set (CBS) limit, and def2-QZVPPD and aug-cc-pVxZ (x = T, Q and 5) basis sets. These calculations indicate that the ground states of the products are (4)Pi(5/2) (OsO+), B-2(1) (OsO2+),(4)Pi(5/2) (OsS+), and (2)A '' (OOsS+) after including empirical spin-orbit corrections. The potential energy surfaces (PESs) for OsSO2+ intermediates, transition states, and all products were also investigated at the B3LYP/def2-TZVPPD level. The PESs show that none of the reactions have barriers in excess of the product endothermicities. Cross sections for OsO+ formation are compared to those from previous guided ion beam studies of related systems (Os+ + O-2 and CO and Re+ + SO2) to evaluate their relative behaviors.