The Schiff base pyridine-2-carboxaldehyde-4-aminoantipyrine(C17H16N4O 1) and its perchlorate(C17H17N4O·ClO4 2) have been prepared and characterized by elemental analysis,IR spectra and single-crystal X-ray crystallography analysis.Both 1 and 2 crystallize in the monoclinic system,space group P21/c.For 1,a = 8.6820(12),b = 24.934(3),c = 7.0064(10) ,β = 97.942(3)°,V = 1502.2(4) 3,Z = 4,Dc = 1.293 g/cm3,F(000) = 616,μ = 0.084 mm-1,the final R = 0.0592 and wR = 0.1244.For 2,a = 5.9302(2),b = 20.347(7),c = 14.663(6) ,β = 90.200(9)°,V = 1769.2(11) 3,Z = 4,Dc = 1.475 g/cm3,F(000) = 816,μ = 0.254 mm-1,the final R = 0.0533 and wR = 0.0819.As expected,both molecular structures of 1 and 2 adopt a trans configuration about the central C=N double bond.2 is an ionic compound with the protonation at N(1) of pyridine-2-carboxaldehyde-4-aminoantipyrine.
