Picryl iodide

Bond lengths for the o- and p-nitro groups in picryl iodide are quite different.38 Distance a is 1.45 A, whereas b is 1.35 A. The obvious explanation is that the oxygens of the p-nitro group are in the plane of the ring and thus in resonance with it, so that b has partial... 

Fig. 224. Picryl iodide. Vector map, 110 projection. (Huse and Powell, 1940.)...

Many ingenious applications of vector maps have been suggested and used. For instance, pairs of isomorphous crystals are often used for difficult structures, and if the replaceable atoms are not at symmetry centres, it is necessary to find their parameters. If tlie replaceable atoms are heavy enough, they may be located readily as in picryl iodide if not, the vector maps of the two isomorphous crystals may be compared the differences indicate which peaks are due to the replaceable atoms. Alternatively, a Patterson synthesis may be computed in which the differences between structure amplitudes of corresponding... 

Another use for reagent is for reductive elimination of halogen from at least some nitroaryl halides, for example picryl iodide " ... 

Picryl iodide (2-iodo-lrlJ-trinitrobenzene) [4436-27-5] M 340.0, m 164-165 . Ciystallise the iodide from benzene. [Beilstein 5 III 647,5IV 758.]... 

---