Synthesis, spectral, biological, and computational studies of template engineered macrocyclic metal complexes

Abstract

A series of macrocyclic Cu²⁺, Ni²⁺, and Co²⁺ complexes was synthesized using a template reaction between triethylenetetramine and dibenzoylmethane. These complexes may be represented by the general formula [M(C₂₁H₂₆N₄)X₂], where M = Cu²⁺, Ni^2+, and Co²⁺ and X = NO₃ˉ, Clˉ, and CH₃COOˉ. Various techniques, including elemental analysis, molar conductance, magnetic moment, PXRD, thermal investigations, EPR, IR, UV-visible, and mass spectral studies, were used to characterize the synthesized complexes. Their results suggested the distorted octahedral geometry for copper complexes and octahedral geometry for nickel and cobalt complexes. All complexes showed molar conductance in the range of 8–20 ohm⁻¹ cm² mol⁻¹ that indicated the non-electrolytic nature. The DFT studies of all complexes were also performed to analyze the stability of complexes. Antibacterial activities of all complexes were also examined, and it was observed that complexes [Ni(C₂₁H₂₆N₄)(Cl)₂] and [Co(C₂₁H₂₆N₄)(Cl)₂] exhibited remarkable antibacterial activity. Moreover, complex [Co(C₂₁H₂₆N₄)(NO₃)₂] showed miraculous antioxidant activity, even better than that of ascorbic acid and other complexes. The docking studies of [Ni(C₂₁H₂₆N₄)(Cl)₂] and [Co(C₂₁H₂₆N₄)(Cl)₂] were also performed to enforce the results obtained from the antibacterial study of these complexes. Furthermore, the drug-likeness property of all complexes was also evaluated with the help of ADMET studies.

Graphical abstract

Keywords:

• Antimicrobial
• macrocyclic complexes
• template
• antioxidant

Acknowledgment

The authors are thankful to the Department of Chemistry, Kurukshetra University, Kurukshetra for providing the necessary research facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Author Ramesh Kumar is thankful to Kurukshetra University, Kurukshetra for providing funds in the form of the minor research project (No. DPA-I/32/22MRP/2358-2500). Co-authors, Jai Kumar and Arti Jangra, are highly thankful to University Grant Commission, New Delhi for providing financial assistance in the form of a Senior Research Fellowship.