Abstract
A crystal structure determination confirmed that the product from 7-chloroquinilin-4-ylhydrazine and 4-methoxycinnanamic acid had been isolated from MeOCH2CH2OH solution as [(E)-N′-7-chloro-4-(4-methoxycinnamolyhydrazinyl)quinoline, 1. In contrast, recrystallization of the 2-MeO derivative, 2, from the same solvent, produced a 1 : 1 co-crystalline mixture of two tautomers, namely (E)-N′-7-chloro-4-(2-methoxycinnaämolyhydrazinyl)quinoline and 7-chloro-4(1 H)quinolinone 3-(2-methoxycinnamoyl)hydrazone, molecules A and B, respectively. Molecules 1 and 2A have “L”-shapes and, in general, have very similar conformations, which differ from that of 2B, mainly arising from the rotation about the (O)C—N(N) bond within the linker unit between the quinolone and methoxyphenyl rings. In both 1 and 2, the 3-dimensional supramolecular arrangements involve strong N—H…N, N—H…O, C—H…O and C—H…π hydrogen bonds, while additionally in 2, there are π…π, C—Cl…π and C—H…Cl intermolecular interactions.Keywords: X-ray crystallography; Tautomers; 4-(Cinnamolyhydrazinyl)quinolones; 4-(1H)quinolinone 3-(cinnamoyl)hydrazones; Supramolecular arrays Document Type: Research Article DOI: http://dx.doi.org/10.1524/zkri.2013.1596 Publication date: 22 de abril de 2013