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Alan Howie R.,University of Aberdeen | Da Silva Lima C.H.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Kaiser C.R.,Federal University of Rio de Janeiro | De Souza M.V.N.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Wardell S.M.S.V.,CHEMSOL
Zeitschrift fur Kristallographie | Year: 2010

The crystal structures of six (pyrazinecarbo-nyl)hydrazone di-substituted benzaldehyde derivatives | N2C4H3CONHN=CHC 6H3XY: X.Y = 2.3-Cl2; 2,3-(MeO)2; 2,4-F2; 2,4-Me2; 3-HO-4-MeO; 3-Me6-4-HO] and one tri-substituted benzaldehyde derivative, [N2C4H 3CONHN=CHC6H2X3: X3 = 3,4,5-(MeO)3] are reported. In all cases extensive intermolecular C-H X (X = O, N or π-ring) hydrogen-bonding is present in which the the oxygen atoms of OH and OMe substituents act as hydrogen-bond acceptors and C-H bonds of methyl groups act as hydrogen-bond donors. The connectivity attained is one-dimensional in chains or ribbons in the 2.3-(OMe)2 and 2,4-Me2 derivatives, three dimensional only in the case of the 3-MeO-4-HO derivative and two dimensional in layers of molecules otherwise. It is concluded, therefore, that the bulky nature of the substituents limits the connectivity attainable in this series of compounds. © by Oldenbourg Wissenschaftsverlag, München. Source


Alan Howie R.,University of Aberdeen | Da Silva Lima C.H.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Kaiser C.R.,Federal University of Rio de Janeiro | De Souza M.V.N.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Wardell S.M.S.V.,CHEMSOL
Zeitschrift fur Kristallographie | Year: 2010

The crystal structures of hydrates of five substituted benzaldehyde (pyrazinecarbonyl)hydrazone derivatives |N2C4H 3CONHN=CHC6H5-nXn m H2O: m = 1, n 1. X = 3-HO: m 1. n 2. X2 = 2,5-(HO)2; m = 1, n = 2, X2 = 2,4-(MeO)2; m = 2.5, n = 2, X2 = 3,4- (MeO)2; m=3. n = 1. X = 4-HO] are reported. In all cases the water molecules participate in strong hydrogen- bonds extending and partially replacing the weak intermo- lecular C-HX (X = O, N or φ-ring) hydrogen-bonding and φ φ it interactions normally present in anhydrous structures of compounds of this type. © by Oldenbourg Wissenschaitsverlag, München. Source


Alan Howie R.,University of Aberdeen | Da Silva Lima C.H.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Kaiser C.R.,Federal University of Rio de Janeiro | De Souza M.V.N.,Institute Of Tecnologia Em Farmacos Farmanguinhos | Wardell S.M.S.V.,CHEMSOL
Zeitschrift fur Kristallographie | Year: 2010

The crystal structures of seven (pyrazinecar-bonyl)hydrazone mono-substituted benzaldehyde derivatives, N2C4H 3CONIIN CHC6H4X (1: X = CN, OMe, OEt or NO 2) are reported. In all cases extensive intermole-cular C - H X (X = O, N or φ-ring) hydrogen-bonding is present in which the nitrogen atom of ρ-CN and one oxygen atom of 0-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, φ φ interactions and, in the case of (1: X = m-OEt) C - H N and C - H φ-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). φ by Oldenbourg Wissenschaftsverlag, München. Source

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