The title compound, C(20)H(14)N(2)O(4)·H(2)O, was synthesized by the reaction of fluorescein and hydrazine hydrate in ethanol. In the crystal structure, the organic mol-ecules are linked into extended two-dimensional networks by inter-molecular hydrogen bonding. Additional face-to-face π-π stacking inter-actions between the phenolic benzene rings in two adjacent mol-ecules [centroid-to-centroid...

The asymmetric unit of the title compound, C(14)H(12)N(2)O(5)S, contains two independent mol-ecules. The dihedral angles between the aromatic rings are 82.03 (9) and 79.47 (8)° in the two independent mol-ecules. In the crystal, the two mol-ecules in the asymmetric unit are linked into dimers via pairs of N-H⋯O(S) hydrogen bonds to generate C(4) chains.

In the title mol-ecule, C(14)H(13)IN(2)O(3)S, the dihedral angle between the planes of the benzene and toluene rings is 84.3 (3)°. The mol-ecule displays a trans conformation with respect to the C=N bond. There is an intra-molecular O-H⋯N hydrogen bond with the azomethine N atom as acceptor. In the crystal, N-H⋯O hydrogen bonds connect the mol-ecules into chains running along the b axis.

The title mol-ecule, C(14)H(10)N(4)O(6), crystallizes with one half-mol-ecule in the asymmetric unit; the mid-point of the N-N bond lies on an inversion centre. The nitro and amide groups are twisted with respect to the benzene ring, making dihedral angles of 14.6 (5) and 31.1 (5)°, respectively. In the crystal structure, mol-ecules are linked through N-H⋯O hydrogen bonding between the imino an...

In the title compound, C(12)H(14)N(4)·6H(2)O, the two pyrimidine rings make a dihedral angle of 5.285 (6)°. Inter-molecular O-H⋯O hydrogen bonds link the six water mol-ecules, generating edge-fused four-, five- or six-membered ring motifs and forming two-dimensional sheets. The sheets are stabilized by the formation of O-H⋯N hydrogen bonds between the water mol-ecules and the bipyrimidine mol-e...

The asymmetric unit of the title compound, C(12)H(14)N(2)O(4), contains two independent mol-ecules. In one independent mol-ecule, the furanyl fragment is rotationally disordered between two orientations in a 0.625 (6):0.375 (6) ratio. In the crystal, inter-molecular pyrimidine-pyrimidinone N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric tetra-mers, which are further associated int...

The asymmetric unit of the title compound, C(15)H(14)N(2), contains two mol-ecules. The amine NH group connects two aromatic systems with similar C-N-C bond angles of 120.96 (16) and 119.75 (16)° for each independent mol-ecule. In contrast, the dihedral angles between the benzene rings are significantly different for the two independent mol-ecules, viz. 69.1 (2) and 79.9 (2)°.

There are two independent mol-ecules in the asymmetric unit of the title compound, C(15)H(14)BrNO(3), with very similar geometrical parameters. Each mol-ecule adopts the phenol-imine tautomeric form, with strong intra-molecular O-H⋯N hydrogen bonds. The two mol-ecules are non-planar, the dihedral angles between the two aromatic rings being are 24.6 (2) and 30.30 (13)°.

In the title compound, C(14)H(15)N(5)O(2), the whole mol-ecule apart from the terminal C atoms of the isopropyl group is located on a crystallographic mirror plane. An intra-molecular C-H⋯N hydrogen-bonding inter-action may stabilize the mol-ecular conformation. The crystal packing features weak slipped π-π inter-actions between the pyrimidine and the phenyl rings of symmetry-related mol-ecules...

The title compound, C(19)H(14)O, contains two independent mol-ecules with the same s-cis conformation for the ketone unit. Both mol-ecules are non-planar with dihedral angles of 51.9 (1) and 48.0 (1)° between the benzene ring and the naphthalene ring system. In the crystal, neighboring mol-ecules are stabilized by intermolecular C-H⋯π inter-actions, giving a two-dimensional supra-molecular arra...