Crysta1 structure of dunnione p-bromophenylhydrazone

The crysta1 structure of dunnione p-bromopheny1hydrazone has been determined by single-crysta1 X-ray diffraction methods at 295 K, the structure being refined to a residua1 of 0-054 for 1429 ‘observed’ reflections. Crysta1s are tric1inic, PI, a 15-620(8), b 8-804(4), c 7-439(4) Â, α 68-03(4), β 89-85(4), γ 77-44(4)°, Z 2. The conjugation throughout the molecule is extensive and the crysta1 packing is dominated by intermolecu1ar charge-transfer interactions. Bonding in the hydrazone moiety 1ies intermediate between those expected for hydrazone and azo forms.