Scheme 1From: Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyesThe equilibrium between the azo form (A) and the hydrazone form (B) of 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridones. (X = H (1), OH (2), OCH3 (3), CH3 (4), Cl (5), Br (6), I (7), F(8), CN (9), COOH (10), COCH3 (11), NO2 (12)).Back to article page