• Dr. Sumit Kumar
• Vinod Kumar

The importance and versatility of ligands with amide groups helped in the selection of this class of ligands and their complexes for the study. The synthesis, spectroscopic analysis, and biological investigations of amide complexes containing Zn (II) ions that develop from heterocyclic amines are presented in this paper. Four ligands, including their complexes with Zn (II), have been synthesized from 2-(Methylamino) pyridine. A method of producing complexes by microwave irradiation has been developed in accordance with the green chemistry approach. The complexes have been described using magnetic susceptibility studies, electronic, infrared, and ESR spectra, as well as elemental analysis. The electronic spectra of the zinc complexes with amide group containing ligands show weak absorption in the visible region. The observed spectra of the Zn (II) complexes with the ligands exhibit two bands in the region 20000 cm-1 and 26000 cm-1 assignable to: 6A1g 4T2g & 6A1g  4Eg, 4A1g (4G) transitions. The electronic spectral transitions of zinc complexes with the ligands are typical of tetrahedral environment around the zinc. Complexes of bivalent zinc are known in both; high spin (S=5/2) and low spin (S = 1/2) states. Because of the additional stability of the half filled d-orbitals, Zinc (II) generally forms high spin complexes which have an orbitally degenerate 6S ground state term and the spin only magnetic moment of 5.9 ± 0.1 BM as expected which will be independent of temperature and stereochemistry. The magnetic susceptibility measurements have been carried out in the polycrystalline state at room temperature. All the Zn (II) complexes have magnetic moment values in the range 5.6-6.02 BM indicating the presence of five unpaired electrons and hence, these are high spin complexes with tetrahedrally coordinated zinc. The IR bands due to amide v (N-H) mode observed at 3209-3397 cm-1 for the free amide group containing ligands are shifted to higher frequencies indicating non- participation of nitrogen atom of amide group in coordination. Amide I bands due to v (C=O) shift negatively opposite to that of v (N-H) in the complexes suggesting carbonyl oxygen coordination. In complexes, pyridyl nitrogen participates in bonding, which has been confirmed by the 20-60 cm-1 negative shifting of pyridyl ring peak in complexes in comparison of ligands. Complex synthesis using microwaves has been proved to be more straightforward, practical, and environmentally benign. Compounds' antimicrobial properties were also tested against Staphylococcus aureus and Escherichia coli.

Zinc (II), Microwave, Amide

"Microwave Assisted Synthesis, Spectral and Antibacterial Investigations on Complexes of Zn (II) With Ligands Derived From 2-(Methylamino) pyridine", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 5, page no.j84-j89, May-2025, Available :http://www.jetir.org/papers/JETIR2505A08.pdf

"Microwave Assisted Synthesis, Spectral and Antibacterial Investigations on Complexes of Zn (II) With Ligands Derived From 2-(Methylamino) pyridine", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 5, page no. ppj84-j89, May-2025, Available at : http://www.jetir.org/papers/JETIR2505A08.pdf