Assessment of halogen-bond induced cocrystallization of 1,3,5-trihalo-2,4,6-trifluorobenzenes with 2,3,5,6-Tetramethylpyrazine

Cocrystallization of each of 1,3,5-trichloro-2,4,6-trifluorobenzene, 1,3,5-tribromo-2,4,6-trifluorobenzene, and 1,3,5-triiodo-2,4,6-trifluorobenzene with 2,3,5,6-tetramethylpyrazine via selected mechanochemical and solution methods is assessed. In lieu of single crystals of suitable quality for structure determination via single-crystal Xray diffraction, powder X-ray diffraction and C-13 cross-polarization magic-angle spinning solid-state NMR spectroscopy are used to qualitatively assess halogen-bond induced cocrystal formation. The results suggest a rich polymorphic landscape worthy of further study.

Automated summary

The cocrystallization of 1,3,5-trichloro-2,4,6-trifluorobenzene, 1,3,5-tribromo-2,4,6-trifluorobenzene, and 1,3,5-triiodo-2,4,6-trifluorobenzene with 2,3,5,6-tetramethylpyrazine was assessed using mechanochemical and solution methods. Instead of single crystals, powder X-ray diffraction and solid-state NMR spectroscopy were used to qualitatively evaluate the formation of halogen-bond induced cocrystals. The results indicate a diverse polymorphic landscape that deserves further study.