Synthesis, characterization and metal ion sensing properties of novel pyridone derivatives phthalocyanines

The design of novel substituted phthalocyanines closely follows the requirement of their planned applications. In this study, synthesize of novel pyridone derivatives metal-free and symmetrical cobalt(II) phthalocyanines was carried out to improve brightness. For this purpose; starting with 4-nitrophthalonitrile and 4-hydroxy-6-methyl-3-nitro-2-pyridone, 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile was prepared. Then 2(3),9(10),16(17),23(24)-tetrakis[6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy] metal-free phthalocyaninato and 2(3),9(10), 16(17),23(24)-tetrakis[6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy] phthalocyaninato Co(II) were synthesized by using 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile, lithium metal and cobalt(II) acetate tetrahydrate in amyl alcohol, respectively. The sensing behavior of the film of derivatives metal-free and symmetrical cobalt(II) phthalocyanines for the online detection of heavy metal ions in water samples was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the analytes on the coating surface cause a reversible negative frequency shift of the resonator. Quartz crystal microbalance (QCM) functionalized with phthalocyanine, derivatives metal-free and symmetrical cobalt(II) phthalocyanines, are demonstrated to be sensors for the detection of heavy metal ions like Cd²⁺, Zn²⁺, Cu²⁺, Cr²⁺ and Co²⁺. Thus, QCM based sensor arrays are considered a promising platform for the direct analysis of aqueous samples.