A selected ion flow tube (SIFT) has been used to study the reactions of S 2 + with a series of organic molecules (as well as H 2, CO, NH 3, NO and NO 2). These include the hydrocarbons, C 2H 4, C 2H 6, CH 2CCH 2, CH 3CHCH 2 and C 3H 8; alcohols and thiols, CH 3OH, C 2H 5OH, CH 3SH and C 2H 5SH; ethers (CH 3) 2O and (C 2H 5) 2O; aldehydes and ketones, CH 3CHO, C 2H 5CHO and (CH 3) 2CO; and carboxylic acids and esters, HCO 2H, HCO 2CH 3, HCO 2C 2H 5, CH 3CO 2H, CH 3CO 2CH 3, CH 3CO 2C 2H 5, C 2H 5CO 2H, C 2H 5CO 2CH 3 and C 2H 5CO 2C 2H 5. The rate coefficients are generally close to the collisional values, with exceptions among the reactions involving the smaller molecules. Most prevalent are abstraction reactions leading to formation of the thiosulfeno radical, HS 2, or its protonated form; three-body associations; and channels leading to formation of the acetyl and propionyl cations, CH 3CO + and C 2H 5CO +, respectively. Only in reactions involving the alkenes is cleavage of the SS bond of S 2 + observed. The isomeric molecules in the data set generally react very differently, as would be expected from reactivity controlled by the position and complexity of the functional groups. The data are discussed in terms of reaction mechanisms, thermodynamics, and implications for interstellar chemistry.