organic compounds
The title isomers, namely 3-chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (I), and 4-chloro-N-[1-(1H-pyrrol-2-yl)ethylidene]aniline, (II), both C12H11ClN2, differ in the position of the chlorine substitution. Both compounds have the basic iminopyrrole structure, which shows a planar backbone with similar features. The dihedral angle formed by the planes of the pyrrole and benzene rings is 75.65 (7)° for (I) and 86.56 (8)° for (II). The H atom bound to the pyrrole N atom is positionally disordered and partial protonation occurs at the imino N atom in (I), while this phenomenon is absent from the structure of (II). Packing interactions for both compounds include intermolecular N—HN hydrogen bonds and C—Hπ interactions, forming centrosymmetric dimers for both (I) and (II).
metal-organic compounds
The title complex is composed of two deprotonated N,N′-bidentate 2-[(phenylimino)ethyl]-1H-pyrrol-1-ide ligands around a central NiII cation, with the pyrrolide rings and imine groups lying trans to each other. Molecules are linked into simple chains by two C—Hπ hydrogen bonds, one of which is intermolecular with a phenyl β-C atom as donor, while the other is intramolecular with a pyrrole β-C atom as donor.
organic compounds
Two basic heterocyclic imino structures display a planar backbone with similar features, but differ in the heterocyclic atoms located in the five-membered rings, i.e. N and S. In the pyrrole, centrosymmetric iminopyrrole dimers are assembled by means of two inverted N—HN hydrogen bonds and two inverted C—Hπ interactions. In the thiophene, however, molecules are linked by nonclassical C—HN hydrogen bonds in which the molecules play the roles of both hydrogen-bond donors and acceptors, resulting in one-dimensional supramolecular chains.