Schematic diagram showing some of the possible chemical pathways starting from C₂H₂, C₂H₄, and C₂H₆ (inner circle) in the formation of COMs via activation of the closed-shell molecules by OH and H radicals, which forms the four radicals shown in the intermediate circle. It should be noted that not all of the possible reaction paths are indicated in the diagram. The COMs shown in the outer circle are: (1) CHOHCHNCO; (2) vinyl cyanide, C₂H₃CN; (3) 1,2-ethenediol, (CHOH)₂; (4) ethyl mercaptan, C₂H₅SH; (5) ethyl isocyanate C₂H₅NCO; (6) ethanol, C₂H₅OH; (7) ethanolamine, NH₂CH₂CH₂OH; (8) ethylamine, C₂H₅NH₂; and (9) vinyl mercaptan C₂H₃SH.