Ambidentate behavior of pentadentate N,N′-bis(2-hydroxyphenyl)-pyridine-2,6-dicarboxamide towards transition metal(II) salts

Abstract

Complexes of Co(II), Ni(II), Cu(II), Mn(II), Zn(II) and Cd(II) with N,N¢-bis(2-hydroxyphenyl)pyridine-2,6-dicarboxamide have been synthesized and characterized by elemental analysis, conductivity measurements, spectral (electronic, i.r., n.m.r. and e.p.r.), electrochemical and thermal studies. I.r. studies show that the ligand behaves in an ambidentate way. It coordinates through the pyridine nitrogen, two amide oxygens and two phenolic oxygens in the Co(II), Ni(II), and Cu(II) complexes, whereas in the Mn(II), Zn(II) and Cd(II) complexes it coordinates through the pyridine nitrogen, two uncharged amide nitrogens and two-phenolic oxygens under similar experimental conditions.

Ion recognition properties of new pyridine-2,6-dicarboxamide bearing propeller-like pendant residues: multi-spectroscopic approach

“…Infrared spectroscopy is widely used as a method for the determination of the mode of metal cation binding by amide ligands [16,64,65,72,73]. An amide backbone can be engaged in complex formation via oxygen or nitrogen of amide residue what is seen by shift of the I, II, and III amide band.…”

Antibacterial Efficacy of N-(4-methylpyridin-2-yl) Thiophene-2-Carboxamide Analogues against Extended-Spectrum-β-Lactamase Producing Clinical Strain of Escherichia coli ST 131

“…Proteins’ crucial building block, the carboxamide bond (-CO-NH-), has drawn much interest because it resists hydrolysis. Because of the ability to create peptides from extremely basic amino acid substrates, this phenomenon is essential in biological systems [ 21 , 22 , 23 , 24 ]. The expression of efflux systems that prevent the antibacterial drug from reaching its intracellular target, the modification of the drug’s target site, or the production of an alternative metabolic pathway that avoids the drug’s action are all possible effects of acquired resistance genes in bacteria [ 24 ].…”

Synthesis of Functionalized N-(4-Bromophenyl)furan-2-carboxamides via Suzuki-Miyaura Cross-Coupling: Anti-Bacterial Activities against Clinically Isolated Drug Resistant A. baumannii, K. pneumoniae, E. cloacae and MRSA and Its Validation via a Computational Approach

“…The carboxamide bond (–CO–NH–) in proteins is indeed a pivotal building unit that has gotten a lot of attention due to its great hydrolysis resistance. This phenomenon is significant in biological systems because it allows peptides to be built from very simple amino acid substrates [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Moreover, Suzuki–Miyaura cross-coupling is an efficient tool that involves a pseudohalide/organohalide electrophile and organoboron nucleophile to establish a carbon–carbon bond in the presence of a catalyst [ 23 , 24 ].…”