In the title compound, C(15)H(14)O(5), an intramolecular O-H⋯O hydrogen bond occurs. In the crystal, the molecules form inversion dimers linked by pairs of O-H⋯O bonds, which are further linked by C-H⋯O interactions.

In the title compound, C18H14N6O2, the benzene ring is slightly twisted out of the plane of the 1,2,3-triazole ring (r.m.s. deviation = 0.010 Å), forming a dihedral angle of 6.20 (13)°. The nine non-H ring atoms of the fused five- and six-membered ring system are almost coplanar (r.m.s. deviation = 0.032 Å). The near coplanarity in the central residue is consolidated by an intra-molecular bifur...

In the title compound, C(12)H(7)Cl(2)FN(2)O, the dihedral angle between the phenyl and pyridine rings is 42.5 (2) Å and an intramolecular N-H⋯N hydrogen bond occurs. The crystal structure is stabilized by C-H⋯O, C-H⋯F and C-Cl short contacts.

IN THE CATION OF THE TITLE COMPOUND [SYSTEMATIC NAME: (RS)-4-(3-carb-oxy-1-ethyl-6,8-difluoro-4-oxo-1,4-dihydro-quinolin-7-yl)-2-methyl-piperazin-1-ium 2,4,6-trinitro-phenolate], C(17)H(20)F(2)N(3)O(3) (+)·C(6)H(2)N(3)O(7) (-), the piper-azine ring adopts a slightly distorted chair conformation and contains a protonated N atom. An intra-molecular O-H⋯O hydrogen bond occurs in the cation. The di...

The title compound, C(12)H(21)NO(4), a γ-aminobutyric acid derivative, crystallizes with two mol-ecules in the asymmetric unit. The crystal structure is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds, forming a strand. An intramolecular N-H⋯O hydrogen bond is also observed.

The title compound, C(17)H(18)N(6)O(2)·0.5CH(3)OH, exists in the double keto form and adopts a highly puckered geometry, stabilized by intra-molecular N-H⋯O and N-H⋯N hydrogen bonds. Inter-molecular N-H⋯N hydrogen bonds and π-π stacking inter-actions [centroid-centroid separation = 3.654 (1) Å] assemble the mol-ecules into chains running in the [111] direction. The methanol solvent mol-ecule is...

In the title salt, C(20)H(24)FN(2)O(2) (+)·0.5C(4)H(2)O(4) (2-), the fumarate anion is located on an inversion centre. In the cation, the two benzene rings are nearly perpendicular to each other, making a dihedral angle of 87.41 (10)°. The cation is linked to the anion by a bifurcated N-H⋯O hydrogen bond. Classical O-H⋯O and weak C-H⋯F hydrogen bonding is also present in the crystal structure. ...

The solvatochromic emission properties of five naphthoylurea derivatives with different substitution patterns at the naphthoylurea functionality were investigated, with a particular focus on the influence of inter- and intramolecular H-bonding interactions. The bathochromic shifts of the emission maxima correlate well with the acceptor number or Catalán's acidity of the solvent (Δλ = 47-86 nm),...

The asymmetric unit of the title compound, C(11)H(10)N(6)O(3)S, contains two independent mol-ecules, each of which is stabilized by an intra-molecular N-H⋯O hydrogen bond, forming an S(6) ring motif. In one mol-ecule, the pyrazole ring forms a dihedral angle of 10.93 (14)° with the benzene ring. The corresponding dihedral angle in the other mol-ecule is 7.03 (14)°. In the crystal, mol-ecules ar...