Authors: Howie, R.A.; Lima, C.H.S.;Kaiser, C.R.; De Souza, M.V.N.; Wardell, J.L.; Wardell, S.M.S.V.
Source: Zeitschrift für Kristallographie, v. 225, p. 19-28, 2010.
Publisher: De Gruyter
Abstract
The crystal structures of seven (pyrazinecarbonyl)hydrazone mono-substituted benzaldehyde derivatives, N2C4H3CONHN=CHC6H4X (1: X = CN, OMe, OEt or NO2) are reported. In all cases extensive intermolecular C–H · · · X (X = O, N or π-ring) hydrogen-bonding is present in which the nitrogen atom of p-CN and one oxygen atom of o-NO2 substitutents act as hydrogen-bond acceptors and C–H bonds of the methyl groups of the p-OME and m-OEt substituents act as hydrogen-bond donors. While the m-OMe substituted compound exhibits only one-dimensional connectivity in the form of face to face ribbons of molecules two-dimensional layer connectivity is observed in all other cases. If, however, π · · · π interactions and, in the case of (1: X = m-OEt) C–H · · · N and C–H · · · π-ring contacts, which arise between the layers as they are stacked, are taken into account three-dimensional connectivity is the norm for the layer structures except for that of (1: X = o-Et).Keywords: (Pyrazinecarbonyl)hydrazone; pi … pi interactions; Hydrogen bonds; X-ray diffraction; Crystal structure analysis Document Type: Research Article DOI: http://dx.doi.org/10.1524/zkri.2010.1209 Publication date: 19 de Abril de 2010
