Síntese, caracterização e avaliação antimicrobiana de um novo composto de Co(II) com N(4-piridil)isonicotinamida

Abstract

The World Health Organization (WHO) has alerted the world population about bacterial resistance in a possible post - antibiotic era, which can cause serious problems to public, social and economic health, globally. Based on this concern, coordination compounds have been shown to be possible candidates in combating bacterial resistance. In this work, we report the synthesis, characterization and microbicidal investigation of the cobalt +2 complex with the ligand N-(4-pyridyl)isonicotinamide (4-pina), in addition to the acid dissociation properties (pKa) of the ligand 4-pina by ultraviolet visible that demonstrated the existence of two pKa (pKa1 = 2.73 ± 0.02 and pKa 2 = 5.33 ± 0.03). The analysis of medium infrared revealed the formation of new hydrogen interactions with the appearance of a new absorption band in 3339 cm-1 characteristic of N-H, the bands of the amide group, ʋ (C = O) and ʋ (CN), they moved to the region of greatest energy, about 14 cm-1 and 10 cm-1

, respectively, indicating that the coordinated covalent bond is occurring through the pyridine rings. The thermogravimetric analysis TG-DTG and TG-DSC, suggests the possible molecular formula [CoCl2(4-pin)]n, which is corroborated by the elementary analysis of carbon, hydrogen and nitrogen. Microbicidal investigation has shown that the synthesized compound is sensitive to Staphylococcus aureus and Escherichia coli bacteria, in addition to assisting in the phagocytic process of peripheral blood mononuclear cells.