Synthesis, structures, and fluorescent properties of azo anthranilic acid and its Cu(II), Co(II), and Ni(II) complexes

Synthesis, characterization, and biological studies of some biometal complexes

Background

Metal complexes Cu[C13H8O4N]22, Ni[Cl3H8O4N]23, and Co[C13H8O4N]24 of bioinorganic relevance have been synthesized with the Schiff base ligand 2-furylglyoxal–anthranilic acid (FGAA) [C13H9O4N] 1.

All the complexes are well characterized by various spectral and physical methods. The antimicrobial activity of the complexes has been studied against some of the pathogenic bacteria and fungi.

Results

Results indicate that complexes have higher antimicrobial activity than the free ligand. This would suggest that chelation reduces considerably the polarity of the metal ions in the complexes which in turn increases the hydrophobic character of the chelate and thus enables permeation, through the lipid layer of microorganisms. All the complexes were assessed for their anticancer studies against a panel of selected cancer cells HOP62 and BT474 respectively. Results showed that the complexes are promising chemotherapeutic alternatives in the search of anticancer agents. The fluorescence quenching phenomenon is observed in the Schiff base metal complexes.

Conclusion

The octahedral transition metal complexes 2, 3, and 4 have been obtained by treatment of ligand 2-furylglyoxal-anthranilic acid (FGAA) 1 with metal acetate. Complexes under investigations have shown antimicrobial, potential anticancer, and the DNA binding studies.

Graphical abstract

Diverse cobalt(ii) coordination polymers for water/ethanol separation and luminescence for water sensing applications

N,N′-Bis(3-pyridylmethyl)pyromellitic diimide has four conformations, which lead to four types of cobalt(ii) coordination polymers. Such coordination networks can be used for luminescent water sensing and water/ethanol separation.

Synthesis, crystal structure, fluorescence properties of 1D chain Manganese (II) and Cadmium (II) complexes

Two complexes, {[Mn(3-pmpmd)₂(Cl)₂]·2H₂O}_n(1), {[Cd(3-pmpmd) (I)₂]·CHCl₃·H₂O}_n(2), (3-pmpmd, N,N'-bis(3-pyridylmethyl)pyromellitic diimide) were synthesized and characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses, and X-ray single-crystal structure analysis. The conformations of 3-pmpmd ligand affect their structural diversity. Complex 1 is a 1D double chain structure in edge-to-edge arrangement by π⋯π interactions. Complex 2 is a typical 1D zigzag chain structure arranged in a parallel array containing 1D channel to accommodate the chloroform and water guest molecules. Thermal stabilities and fluorescence properties of both complexes were investigated. The solution of complex 2 in DMF can sense for I^- anion by quenching fluorescence intensity, whereas other anions increasing fluorescence intensity.