Mechanochemical synthesis of Ni(II)-tptz complexes with co-ligands: Spectroscopy, DFT, and biological studies

Deepak SENAPATI; Anulipsa  PRIYADARSHINI; Debadutta  SAMAL; P. Ramesh BABU; Satyanarayan  SAHOO; Narayan CHANDRA BERA; Raghabendra  SAMANTARAY; Jagannath PANDA; Rojalin SAHU

doi:10.55713/jmmm.v35i2.2324

Authors

Deepak SENAPATI School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
Anulipsa PRIYADARSHINI School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
Debadutta SAMAL School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
P. Ramesh BABU Department of Engineering Chemistry, College of Engineering, Andhra University, Visakhapatnam, 530003, India
Satyanarayan SAHOO P. G. Department of Chemistry, Berhampur University, Ganjam, 760007, Odisha, India
Narayan CHANDRA BERA School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
Raghabendra SAMANTARAY School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
Jagannath PANDA School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India
Rojalin SAHU School of Applied Sciences, KIIT University, Bhubaneswar, 751024, Odisha, India

DOI:

https://doi.org/10.55713/jmmm.v35i2.2324

Keywords:

Vibrational spectra, Electronic spectra, Ni (II) mixed ligand complexes, DNA binding, Antimicrobacterial study

Abstract

New mixed-ligand Ni(II) complexes [Ni(tptz)(1,10-phen)] (1), [Ni(tptz)(2-Mimd)₂] (2), and [Ni(tptz)Imd)₂] (3) were synthesized via a green, solvent-free mechanochemical approach using ball milling. The primary ligand used was 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz), with secondary ligands being 1,10-phenanthroline, 2-methyl imidazole, and imidazole, respectively. Structural characterization by IR, UV-Visible, photoluminescence spectroscopy, and powder X-ray diffraction, supported by DFT calculations, revealed a distorted square planar geometry for complex 1 and distorted tetrahedral geometries for complex-2 and complex-3. Notably, bathochromic shifts in the UV-Vis spectra confirm metal-ligand charge transfer transitions and extended π-delocalization. Powder XRD analysis determined average crystallite sizes of 17.86 nm (1), 25 nm (2), and 14.7 nm (3). DNA-binding studies against calf thymus DNA exhibited bathochromic and hypochromic shifts, indicating an intercalative binding mode. Antibacterial evaluation showed that complexe-2 and complex-3 exhibited enhanced activity against Bacillus subtilis and Escherichia coli, with inhibition zones up to 16 mm, compared to their uncoordinated ligands. These results highlight the potential of Ni(II) coordination complexes as bioactive agents.

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