organic compounds
Open access
The title azo molecule, C16H9Br3N2O, adopts a trans conformation with respect to the azo N=N double bond. An intramolecular O—HN hydrogen bond forms an S(6) ring motif. The dihedral angle between the naphthalene ring system and the benzene ring is 33.80 (16)°. In the crystal, molecules are stacked in columns along the a axis by π–π interactions [centroid–centroid distances = 3.815 (3) and 3.990 (3) Å].
organic compounds
Open access
The title zwitterion, C17H14N2O2, crystallizes with two independent molecules in the asymmetric unit, both of which are approximately planar, the dihedral angles between the benzene ring and the naphthalene ring system being 4.39 (12)° in one molecule and 5.83 (12)° in the other, and show an E conformation with respect to the azo double bond. An intramolecular N—HO hydrogen bond in each molecule helps to establish their near planar conformation. In the crystal, molecules are linked through O—HO hydrogen bonds into infinite chains running along the a-axis direction. In addition, the chains are stacked along the b axis via π–π interactions between the benzene and the naphthalene rings of adjacent molecules, the centroid–centroid distances being 3.722 (3) and 3.823 (4) Å.