Crystal Structure of 2-{1-[(1-(2-Pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate,the Product of Template Condensation in the Presence of Cr(III)

Abstract  In an attempt to synthesize a Cr(III) complex of 2′-1-(2-pyridinyl)ethylidene]oxamohydrazide an azine product 2-{1-(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate was obtained by an electrophilic acyl substitution catalyzed by Cr(III). Its structure was determined by X-ray crystal analysis and showed significant changes in comparison to the corresponding unprotonated compound. The 2-{1-(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate crystallizes in the space group P2₁/n of the monoclinic crystal system with unit cell parameters a = 14.3809(3) ?, b = 24.1516(5) ?, c = 15.4471(3) ?, β = 99.930(2)°, V = 5284.74(19) ?³ and Z = 12, i.e. three molecules per asymmetric unit. Graphical Abstract  In the template condensation of the 2′-1-(2-pyridinyl)ethylidene]oxamohydrazide in presence of the chromium(III) ion the 2-{1-(1-(2-pyridinio)ethylidene)hydrazono]ethyl}pyridinium diperchlorate was obtained and characterized by NMR spectroscopy and X-ray crystallography. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.