The reactivity of O-2(a (1)Delta(g)) was studied with a series of unions, including -CH2CN, -CH2NO2, -CH2C(O)H, CH3C(O)CH2-, C2H5O-, (CH3)(2)CHO-, CF3CH2O-, CF3-, HC2-, HCCO-, HC(O)O-, CH3C(O)O-, CH3OC(O)CH2 and HS-. Reaction rate constants and production branching ratios were measured. All of the carbanions react through a common pathway to produce their major products. O-2(a) adds across a bond at the site of the negative charge. resulting in the cleavage of this bond and the O=O bond. Oxyanions react through a hydride transfer to produce their major products. Proton transfer within these product ion-dipole complexes can occur, where the final branching ratios reflect the basicity of the resulting anions. Several of these anions (CF3-, HC2-, CH3OC(O)CH2) were also found to undergo several sequential reactions within a single encounter. These three basic types of mechanisms are Supported by Calculations; it potential energy diagram for each type Of reaction has been calculated. Additionally, six Of these reactions had been qualitatively studied before; our results are in agreement with previous data.