Synthesis, characterization and in vitro cytotoxicity of Au(I) carbene complexes

•Gold(I) carbene complexes (1–4) were prepared by the reaction of (1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidenegold(I)chloride) (Au(Ipr)Cl) and four different N-substituted imidazolidine-2-thiones.•Characterization of complexes (1–4) through elemental (CHNS) analysis, various spectroscopic techniques, FTIR and NMR (1H and 13C) spectroscopy and X-ray diffraction.•These four new gold(I) complexes (1–4) were evaluated for their antitumor activities against A549, MCF7 and HCT15 cell lines using MTT assay.