No abstract

The title compound, C16H11ClN2O2, was obtained by diazotization of 2-amino-4-chlorophenol followed by a coupling reaction with β-naphthol. There are two molecules (A and B) in the asymmetric unit. The crystal structure features only one type of intermolecular interaction, that is strong hydrogen bonds involving the hydroxyl group. The naphthol and phenol fragments attached to the C=N—N— moiety exhibit an s-trans conformation. In addition, those fragments are almost coplanar, subtending a dihedral angle of 13.11 (2)° in molecule A and 10.35 (2)° in molecule B. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (32.1%), C...H/H...C (23.1%), Cl...H/H...Cl (15.2%), O...H/H...O (12.8%) and C...C (9%) contacts.

The title compound, C8H8NO4 +·NO3 −·H2O, crystallizes in the same space group (P21/c) as the previously reported dihydrate form [Liang & Zhu (2010). Acta Cryst. E66, o667], but with two formula units per asymmetric unit instead of one. In the crystal, the components are linked into a three-dimensional network by classical intermolecular O—H...O and N—H...O hydrogen bonds and π–π stacking interactions. A Hirshfeld surface (HS) analysis indicated that the most important contributions to the crystal packing are from H...O/O...H (52.4%), H...H (13.9%) and C...C (11.2%) for one cation and H...O/O...H (46.3%), H...H (20%) and O...C/C...O (10.6%) for the other.

In the title molecular salt, C6H8NO+·C2H3O2 −, the cations and anions are linked by O—H...O and N—H...O hydrogen bonds, generating a three-dimensional network.

In the title compound, C15H12N2O3S, there are two molecules (A and B) in the asymmetric unit. The attached phenol and quinoline moieties of each molecule are almost coplanar with a dihedral angle of 6.05 (15)° for molecule A and 1.89 (13)° for molecule B. The crystal structure features N—H...O and C—H...O hydrogen bonds, C—H...π interactions and π–π stacking interactions. Hirshfeld surface analysis indicates that the most significant contacts in the crystal packing are C...H/H...C (29.2%), O...H/H...O (28.6%) and H...H (28.5%).