1,1′-{(Hexane-1,6-diyl)bis[(azaniumylylidene)methanylylidene]}bis(naphthalen-2-olate)

Abstract

The whole molecule of the title Schiff base compound, C28H28N2O2, is generated by inversion symmetry. It is formed from two units of ortho-hy­droxy­naphthaldehyde bridged with 1,6-di­amino­hexane. The N atoms are protonated and, thus, the structure is a bis-zwitterionic compound in the solid state. The zwitterion shows strong intra­molecular N—H⋯O hydrogen bonds between the iminium N and the naphthaleno­late O atoms.

Synthesis, X-ray crystallography, computational studies and catecholase activity of new zwitterionic Schiff base derivatives

“…observed in the keto form, in the enol form or in enol/keto mixtures [7,8]. Another form of the Schiff base compounds is also their zwitterionic form [9][10][11][12]. Zwitterions of Schiff bases have an ionic intramolecular hydrogen bond (N + -H• • •O -) and their N + -H bond lengths are longer than the standard interatomic separations observed in neutral N-H bonds (0.87 Å).…”

Crystal structure of 1,1′-{(dodecane-1,12-diyl)bis[(azaniumylylidene)methanylylidene]}bis(naphthalen-2-olate)

“…The azomethine group >C=N of the Schiff base can form stable metal complexes by coordinating through the nitrogen atom (Ouari et al, 2015b., Ouari et al, 2010. Schiff base ligands have many applications including anti-microbial agents (Köse et al, 2015., Taha et al;., Panneerselvam et al, 2009, anti-tumor agents, (Nasr et al, 2009) and as…”

“…For ultrasonic synthesis of similar compounds, see: Rayati & Abdolalian (2013); Khan et al (2014); Kanagarajan et al (2011). For related crystal structures, see: Ouari et al (2010Ouari et al ( , 2015b; Popović et al (2001); Friscic et al (1998); Bi et al (2012); Temel et al (2010). For their applications, see: Kö se et al (2015); Grivani et al (2013); Amin et al (2010); Panneerselvam et al (2009); Nasr et al (2009); Nejo et al (2009); Taha et al (2012 Table 1 Hydrogen-bond geometry (Å , ).…”

Crystal structure of 4-bromo-2-(1H-imidazo[4,5-b]pyridin-2-yl)phenol

“…For the photoluminescence of the title compound, see: Kö se et al (2015); Pal et al (2015); Ray et al (2014). For the literature method used to prepare the title compound, see: Ouari et al (2015a). For the crystal structure of a related compound, see: Belguedj et al (2015 Table 1 Hydrogen-bond geometry (Å , ).…”

“…The title compound was prepared following a literature method (Ouari et al, 2015a). To a MeOH solution (15 ml) of 5bromosalicylaldehyde (0.122 g, 1 mmol) was added drop wise to a MeOH solution (5 ml) of 2,3-diaminopyridine (0.109 g, 1 mmol).…”