Synthesis, Characterization, and Potential Applications of Novel Schiff Base Metal(II) Complexes Derived from 3-Hydroxy-2-Naphthoic Hydrazide and 3-Acetyl-2-Hydroxy-6-Methyl-4H-Pyran-4-One

Schiff base metal complexes presents a broad range of opportunities in the industry and pharmaceuticals alike. Here, we present the synthesis and characterization of novel Schiff base metal complexes. The Synthesis of metal(II) complexes of (E)-3-hydroxy-N’-(1-(6-methyl-2,4-dioxo-3,4-dihydro-2H-pyran-3-yl)ethylidene)-2-naphthohydrazide was conducted through a two-pot synthesis method. The mechanism of reaction of the ligand involved the nucleophilic attack of the primary amine (3-hydroxy-2-naphthoic hydrazide) on one of the carbonyl carbon atoms of 3-acetyl-2-hydroxy-6-methyl-4H-pyran-4-one in an alcohol medium to give the ligand. The reaction of the ligand with metal chlorides of Co(II) and Ni(II) afforded two metal complexes. The mass spectrometry and the color and melting point of the sample was analyzed, the Mass Spectra, Percentage Metal and Elemental properties were analyzed as well H1 NMR, C13NMR to confirm the formation of the novel Schiff base metal complexes. While the color and elemental properties gave a satisfactory result, the ligand spectrum gave a molecular ion of 353.087. The M+ ions of 482.0478 and 483.0428 was obtained from the spectra of the complexes respectively. The protons of the methyl groups were seen as singlet peaks at 2.66 and 2.16 ppm. Aromatic C-H of the naphthene ring gave peaks within the range 8.49-7.34 ppm in the spectrum of the ligand. The 13C NMR spectrum of the ligand was used to corroborate inferences drawn from the proton NMR spectrum. The carbon atoms of the carbonyl groups were seen at 181.51 and 168.53, 162.68 ppm. The carbon atom of the azomethine group presented a peak at 162.84 ppm which is indicative of the formation of the Schiff base ligand. The carbon atoms of the naphthene ring were observed at 105.98-129.29 ppm. Carbon atoms of the methyl groups were assigned to the peaks at 17.16 and 19.77ppm confirming the formation of the metal complex. While other characterization attempts proved a successful synthesis of the target Schiff metal complexes, it is recommended for application in the industry and pharmaceuticals.