Hydrogen-bonding and pi-pi stacking interactions in aquachloridobis(1,10-phenanthroline)cobalt(II) chloride dichloridobis(1,10-phenanthroline)cobalt(II) hexahydrate.

The title compound, [CoCl(C(12)H(8)N(2))(2)(H(2)O)]Cl.[CoCl(2)(C(12)H(8)N(2))(2)].6H(2)O, is the first example of a new 1:1 cocrystal of the octahedral [CoCl(2)(phen)(2)] and [CoCl(phen)(2)(H(2)O)](+).

Remarkable pi-pi stacking of dipyrido[f,h]quinoxaline-6,7-dicarbonitrile in its ethanol solvate.

The title compound, C16H6N6 x C2H6O, is an ethanol solvate of an aromatic phenanthroline-based flat ligand. The latter exhibits a remarkable pi-pi stacking in the crystal structure, with interplanar distances of 3.27 and 3.

[R,S]-Ethambutol dihydrochloride: variable-temperature studies of a dimorphic system with very similar packing.

The two polymorphs (Forms I and II) of [R,S]-ethambutol dihydrochloride transform enantiotropically and reversibly in a single-crystal-to-single-crystal phase transformation mode. These structurally very similar forms have been characterized and their thermodynamic relationship has been investigated by variable-temperature solid-state carbon-13 nuclear magnetic resonance, variable-temperature powder X-ray diffraction, differential scanning calorimetry, and optical microscopy. The nuclear magnetic resonance results are compared with those for the two polymorphs of the [S,S] diastereomer with known structures.