Comparison of the structure of ( )-2-(2-benzylidenehydrazinylidene)quinoxaline with those of its chloro- and bromobenzylidene analogues

---

Abstract

(E)-2-(2-Benzylidenehydrazinylidene)quin­oxaline, C₁₅H₁₂N₄, crystallized with two molecules in the asymmetric unit. The structures of six halogen derivatives of this compound were also investigated: (E)-2-[2-(2-chlorobenzylidene)hydrazinyl­idene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(3-chlorobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(4-chlorobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁ClN₄; (E)-2-[2-(2-bromobenzylidene)hydrazinylidene]quinoxaline, C₁₅H₁₁BrN₄; (E)-2-[2-(3-bromobenzylidene)hydrazinylidene]quino­xaline, C₁₅H₁₁BrN₄; (E)-2-[2-(4-bromobenzylidene)hydrazin­yl­idene]quinoxaline, C₁₅H₁₁BrN₄. The 3-Cl and 3-Br com­pounds are isomorphous, as are the 4-Cl and 4-Br compounds. In all of these compounds, it was found that the supramolecular structures are governed by similar predominant patterns, viz. strong intermolecular N-HN(pyrazine) hydrogen bonds supplemented by weak C-HN(pyrazine) hydro­gen-bond interactions in the 2- and 3-halo compounds and by C-HCl/Br interactions in the 4-halo compounds. In all compounds, there are – stacking interactions.

---

Keywords: None Document Type: Research Article DOI: http://dx.doi.org/10.1107/S0108270113015370 Publication date: 13 de Julho de 2013