Gold(I), silver(I) and copper(I) complexes of 2,4,6-trimethylphenyl-3-benzoylthiourea; synthesis and biological applications

摘要

2,4,6-Trimethylphenyl-3-benzoylthiourea (L) and its gold(I), silver(I) and copper(I) complexes were synthesized. Treatment of L with HAuCl4, AgNO3 and CuI in CH3CN afforded complexes of general representation, M(L)X, where M/X = Au/Cl (1), Ag/NO3 (2), Cu/I (3). Reaction with Au3+ salt afforded two products, wherein complex containing Au+ (reduced under normal and aerobic reaction conditions ca. 66% on NMR time scale) was confirmed by X-ray diffraction for a single crystal of complex 1. The minor fraction (ca. 33%, from H-1 NMR data) in the reaction mixture was identified as complex 4 with a general formula [AuL2]Cl-3. Reaction with AgNO3 and CuI exclusively afforded pure products 2 and 3. Ligand L and complexes 1-4 were characterized by UV/visible, FT-IR and H-1-, C-13 NMR spectroscopy. Complex 1 is crystalline in nature and good quality crystals were obtained which allowed for collection of diffraction data and the structure was thus confirmed. Solution state and solid state structures have been compared. The resultant complexes were tested for their cytotoxicity, antibacterial, antifungal, antioxidant and DNA binding activities. Complex 1 (Au based) showed promising activities in comparison with the available selected drugs used as standards. (C) 2020 Elsevier Ltd. All rights reserved.