Heteroleptic Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes: Structural Characterization, Computational Analysis, Tyrosinase Inhibitory, and Biological Effects.

Derivatization of (NHC)M-Cl (M = Ag, Au) with selected sulfur donors from the family of dialkyldithiophosphates and bis(2-mercapto-1-methylimidazolyl)borate ligands gave a series of heteroleptic mononuclear complexes. In single-crystal X-ray diffraction analysis, Ag(I) complexes adopted a trigonal planar geometry, while Au(I) complexes are near-linear. TD-DFT and hole-electron analyses of the selected complexes gave insight into the electronic features of the metal complexes. In vitro cellular tests were conducted on the human cancerous breast cell line MCF-7 using 2 and 8 . The antibacterial activities of complexes 1 , 2 , 3 , 7 , 8 , and IPr-Ag-Cl were also screened against Gram-positive ( Staphylococcus aureus PTCC 1112) and Gram-negative ( Escherichia coli PTCC 1330) bacteria. Antityrosinase and hemolytic effects of the selected compounds were also determined.