Characterization, DFT calculations and antimicrobial assays of some novel nanoparticles mixed ligand complexes of 5-cyano-6-phenyl-2-thiouracil in presence of 1,10-phenanthroline

Some trivalent (Cr(III), Fe(III)) and divalent (Co(II), Ni(II), Cu(II) Zn(II)) combined with synthesized 5-cyano-6-phenyl-2-thiouracil (H2CPT) in presence 1,10-phenanthroline monohydrate (Phen) to produce crystalline and semi-crystalline nanoparticles mixed ligand metal complexes. The separated nanoparticles complexes were investigated by physicochemical, spectroscopic techniques (FT-IR, UV-Vis. and 1H NMR), X-ray powder diffraction (XRD) and thermal analyses (TG-DTG-DTA). The metal complexes were ionic with 1:2 electrolytes for divalent elements and 1:3 electrolytes for trivalent elements. The FT-IR spectra indicated that H2CPT and Phen functioning as bidentate ligand binding to the metal ions via oxygen and nitrogen of cyano group of H2CPT and through two nitrogen of Phen. According to the magnetic moment and UV-vis. spectra the complexes were identified as octahedral geometries. The XRD analysis of the prepared compounds revealed that H2CPT and the complexes of Cr(III), Fe(III), Co(II) and Ni(II) display semi-crystalline peaks while, Cu(II) and Zn(II) complexes were crystalline in nature. The mechanism of the thermal degradation was identified and the kinetic parameters of the disintegration stages were assessed using Coats-Redfern (CR) and Horowitz-Metzger (HM) methods. DFT computations were used to calculate equilibrium geometric parameters and the lowest energy model structures. H2CPT, Phen and their metal complexes were examined for effectiveness towards two G(+), two G(-) bacteria and two fungi. Co(II) complex was significant, highly significant and very highly significant against all tested bacterial and fungi strains compared with H2CPT, Phen, references standard control and all other complexes.

Automated summary

Synthesized 5-cyano-6-phenyl-2-thiouracil (H2CPT) combined with trivalent (Cr(III), Fe(III)) and divalent (Co(II), Ni(II), Cu(II) Zn(II)) metal ions and 1,10-phenanthroline monohydrate (Phen), resulting in crystalline and semi-crystalline nanoparticles mixed ligand metal complexes. Various techniques were used to investigate the physicochemical and spectroscopic properties of the complexes, including FT-IR, UV-Vis, 1H NMR, XRD, and thermal analyses. The complexes exhibited ionic behavior and octahedral geometries, with semi-crystalline or crystalline nature depending on the metal ions. The complexes showed significant antibacterial and antifungal activity, with the Co(II) complex being the most effective.