Numerous gadsolid reactions of nitrogen dioxide with organic substrates are investigated preparatively and mechanistically. Gaseous NO2 reacts with crystalline stable free radicals (nitroxyls 1, verdazyl6) by electron transfer. The nitrite ions formed are irreversibly oxidized by NOz via oxygen atom transfer. Solid cation nitrates are formed quantitatively. Thione bonds of thiohydantoins 8 are transformed to carbonyl bonds with formation of sulfur and ...