The title mol-ecule, C(16)H(13)NO, is twisted, the dihedral angle between the terminal phenyl rings being 68.40 (6)°. In the crystal, C-H⋯O and C-H⋯N inter-actions lead to supra-molecular layers in the bc plane.

The title compound, C(17)H(17)FN(4)O(4), is a derivative of ciprofloxacin [1-cyclo-propyl-6-fluoro-4-oxo-7-(1-piperazin-yl)-1,4-dihydro-quinoline-3-carboxylic acid]. The crystal packing is stabilized by inter-molecular C-H⋯O hydrogen bonds together with π-π electron ring inter-actions [centroid-centroid separations between quinoline rings of 3.5864 (11) and 3.9339 (13) Å]. A strong intra-molecu...

In the title compound, C(12)H(15)O(7)PS, the P atom has a distorted tetra-hedral environment. The P-O-C-C torsion angles deviate significantly from zero [average = 12.0 (3)°], indicating that the bicyclic OP(OCH(2))(3)C cage is strained. In the crystal, weak C-H⋯O inter-actions consolidate the packing.

In the title compound, C(28)H(35)N(3)O(4), the piperidine ring adopts a boat conformation while the piperazine ring adopts a chair conformation with an equatorial orientation of the phenyl groups. The dihedral angle between the mean planes of the benzene rings is 74.14 (8)°. The mol-ecular conformation is stabilized by a weak intra-molecular C-H⋯N inter-action and the crystal packing is stabili...

In the crystal structure of the title compound, C(17)H(10)N(4)O(5), the mol-ecules lie on twofold axes (through the ketone bridge C and O atoms). The dihedral angle between the two phthalazine rings is 52.25 (1)°. In the crystal, inter-molecular N-H⋯O and O-H⋯O inter-actions link the mol-ecules.