Synthesis, and spectroscopic characterizations of gold(III) complexes containing nitrogen-heterocycle based pyridine derivatives as a biomolecular chelates

Three gold(III) nanostructured complexes of nicotinamide (nta), picolinic acid (pica), and isonicotinic acid (inta) were synthesized by the reacted of AuCl3 salt with nta, pica, and inta with 1:2 stoichiometry in the alcoholic medium. The solid products obtained were formulated by comparing experimental and calculated data for microanalytical (C, H, N) and metal. Both produce 1:2 compounds with metal ions. The prepared complexes were characterized by different physico-spectroscopic techniques. The FTIR, and 1H NMR spectral analysis, morphological analysis (scanning electron microscopy SEM, transmittance TEM, and X-ray powder diffraction XRD) of these complexes have been discussed. The conductive behavior of the complexes indicates that all of them behave as electrolytic behavior. The mononuclear gold(III) complexes have formulated as [Au(nta)2(Cl)2].Cl, [Au(pica)2].Cl and [Au(inta)2].Cl. The shifts of the ν(N–H) amino, ν(C=N) pyridine, and ν(C=O) carboxylic stretches have been monitored to find out the donor sites of the ligands. According to the experimental data, the three complexes can be characterized in the solid state as mononuclear, with a four-coordinate stereochemistry. KEY WORDS: Gold complex, Nicotinamide, Picolinic acid, Isonicotinic acid, Nanostructure, Spectroscopic Bull. Chem. Soc. Ethiop. 2025, 39(1), 111-121. DOI: https://dx.doi.org/10.4314/bcse.v39i1.9