Examination of the symmetric Hantzsch 1,4-dihydropyridine ester derivatives of the prototypical nifedipine molecule indicates the tendency of this class of molecule to form a common packing motif. Crystal structure analysis of 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic diesters and analogs reveals that they form extended chains, characterized as the C(6) packing motif, via intermolecular (amine) N-H...O=C (C3,C5 carbonyl) hydrogen bonds. In addition, all the prepared derivatives also satisfy the basic structural requirements for their high binding efficiency to the receptor. The reproducible C(6) packing motif observed among these compounds has a use in the design of solid-state materials.

The structure of the title compound, C(17)H(16)OS, is primarily stabilized by T-shaped and parallel-displaced aromatic clusters. The distances between the centroids of the aromatic pairs are in the range 4.34-5.30 A. In the crystal packing, the molecules dimerize by means of pi-pi interactions of both face-to-face and edge-to-face types, and the aromatic rings associate in a cyclic edge-to-face tetrameric arrangement of the herring-bone type. These herring-bone interactions appear to insulate hydrogen-bond interactions in the crystal structure.

In each of the zinc(II) complexes bis(acetylacetonato-kappa(2)O,O')(1,10-phenanthroline-kappa(2)N,N')zinc(II), [Zn(C(5)H(7)O(2))(2)(C(12)H(8)N(2))], (I), and bis(acetylacetonato-kappa(2)O,O')(2,2'-bipyridine-kappa(2)N,N')zinc(II), [Zn(C(5)H(7)O(2))(2)(C(10)H(8)N(2))], (II), the metal center has a distorted octahedral coordination geometry. Compound (I) has crystallographically imposed twofold symmetry, with Z' = 0.5. The presence of a rigid phenanthroline group precludes intramolecular hydrogen bonding, whereas the rather flexible bipyridyl ligand is twisted to form an intramolecular C-H...O interaction [the chelated bipyridyl ligand is nonplanar, with the pyridyl rings inclined at an angle of 13.4 (1) degrees]. The two metal complexes are linked by dissimilar C-H...O interactions into one-dimensional chains. The present study demonstrates the distinct effects of two commonly used ligands, viz. 1,10-phenanthroline and 2,2'-bipyridine, on the structures of metal complexes and their assembly.

In the title compound, C23H26O3, the three six-membered rings of the xanthene system are non-planar, having total puckering amplitudes, Q T, of 0.443 (2), 0.202 (2) and 0.449 (2) Å. The central ring adopts a boat conformation and the outer rings adopt sofa conformations. The crystal structure is stabilized by van der Waals inter­actions.

In the mol­ecule of the title compound, C18H24N2O2, the piperidine rings are in chair conformations. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen bonding. There are neither C—H⋯π nor π–π inter­actions in the structure.

View of the molecule of compound (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are represented by circles of arbitrary size.

In the mol­ecule of the title compound, C32H28N2O, two of the four phenyl substituents occupy axial and the other two occupy equatorial positions relative to their respective C5N rings of the adamantane framework. The crystal packing is characterized by weak C—H⋯O interactions. The packing features are distinctly different from those of the crystals of the methoxy‐ and chloro‐substituted analogues.

In the title compound, [Zn(C5H7O2)2(C5H5N)], the metal atom has square-pyramidal coordination geometry with the basal plane defined by the four O atoms of the chelating acetyl­acetonate ligands and with the axial position occupied by the pyridine N atom. The crystal packing is characterized by a C—H⋯O hydrogen-bonded ribbon structure approximately parallel to [10].