Potential antitumor gold drugs: DFT and XANES studies of local atomic and electronic structure

Geometry structure optimization of the potential antitumor agent Au(bipy)(OH)2 was carried out by means of density functional theory simulations. The experimental Au L3-edge Xray absorption near edge structure (XANES) spectrum of Au(bipy)(OH)2 was obtained. The theoretical Au L3-XANES spectra of the gold(III) complex Au(bipy)(OH)2 were simulated using both the self-consistent real-space full multiple scattering theory within the muffin-tin approximation for the potential shape and the full-potential finite difference method. The comparison of the theoretical spectra with the experimental XANES is discussed. The exact local atomic structure of gold complex Au(bipy)(OH)2 has been defined by two independent ab initio methods.