The co-crystals of squaric acid with dipyridyl-type ligands, 1 and 2, are isomorphous and form in the triclinic crystal system. The co-crystals contain linear and flat hydrogen-bonded molecular tape structures along the [120] direction (Figure 1). The squarate monoanions form a rare ten-membered dimer linked by two intermolecular O–H···O hydrogen bonds [2.511(3) Å for 1 and 2.503(2) Å for 2]. E...

The title compound, C17H15N3O2, is a monoclinic polymorph (P21/c with Z' = 1) of the previously reported triclinic (P-1 with Z' = 2) form [Gajera et al. (2013 ▸). Acta Cryst. E69, o736-o737]. The mol-ecule in the monoclinic polymorph features a central pyrazolyl ring with an N-bound p-tolyl group and a C-bound 1,3-benzodioxolyl fused-ring system on either side of the C atom bearing the amino gr...

The closed micellar triclinic structure of a fluorescent phasmidic diacetylene (PhDO) has been fixed by topochemical photopolymerization which induced fluorescence quenching to offer a novel method of image photopatterning.

The title compound, C(18)H(14)O, is polymorphic at 123 K. The ortho-rhom-bic form reported herein has two independent mol-ecules in the asymmetric unit, with mol-ecular volume 313.5 Å(3). The previously reported triclinic (P-1) form [Raston & Scott (2000 ▶). Green Chem., 2, 49-52] has mol-ecular volume 309.6 Å(3) at the same temperature. All three mol-ecules deviate significantly and systematic...