[:pb]Authors: Gomes, L. R.; Low, J. N.; Correia, N. R. L.; Nogueira, Thais C. M.; Pinheiro, A. C. ; De Souza, M. V. N.; Wardell, J. L.; Wardell, S. M. S. V.
Source: Zeitschrift fur Kristallographie-Crystalline Materials, v. 234, p. 59-72, 2019
Publisher: De Gruyter
Abstract
The crystal structures of four azines, namely 1-3-bis(4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 1, 1,3-bis(2,3-dimethoxyphenyl)-2,3-diaza-1,4-butadiene, 2, 1,3-bis(2-hydroxy-3-methoxyphenyl)-2,3-diaza-1,4-butadiene, 3, and 1,3-bis(2-hydroxy-4-methoxyphenyl)-2,3-diaza-1,4-butadiene, 4, are reported. Molecules of 3 and 4, and both independent molecules of 2, Mol A and Mol B, possess inversion centers. The central C=N–N=C units in each molecule is planar with an (E,E) conformation. The intermolecular interactions found in the four compounds are C–H···O, C–H–N, C–H—π and π—π interactions. However, there is no consistent set of intermolecular interactions for the four compounds. Compound, 1, has a two-dimensional undulating sheet structure, generated from C–H···O and C–H···N intermolecular hydrogen bonds. The only recognized intermolecular interaction in 2 is a C–H···O hydrogen bond, which results in a zig-zag chain of alternating molecules, Mol A and Mol B. While 3 forms a puckered sheet of molecules, solely via C–H···π interactions, its isomeric compound, 4, has a more elaborate three-dimensional structure generated from a combination of C–H···O hydrogen bonds, C–H···π and π···π interactions.
The findings in this study, based on both PLATON and Hirshfeld approaches, for the four representative compounds match well the reported structural findings in the literature of related compounds, which are based solely on geometric parameters.
Keywords: 1,4-diaryl-2,3-diazabuta-1,3-dienes, azines, crystal structures, hirshfeld surface analysis, intermolecular interactions
Document Type: Research Article
DOI: 10.1515/zkri-2018-2113
Publication date: 2 de julho de 2018[:]