A theoretical study of the mono-substituent effect of superhalogens on the geometric structure, electronic properties, and hydrolysis of cisplatin

Abstract

• The mono-substituent effect of superhalogens (SH) on the geometric structure, electronic properties, and hydrolysis of cisplatin has been studied. • All the geometric parameters, electronic properties, bonding nature, and hydrolysis of X-Pt obviously depend on the atomic number of halogens. • The newly formed Pt-N and Cl-B linkage bonds are proved to be strong polar covalent bonds. • The substitution of Cl by X@B 12 N 12 enhances the polarity and solubility of DDP, but weakens the bond strength of Pt-Cl bond. • F-Pt possesses the highest stability and lowest total energy barrier for generating di-aquated species among these X-Pt compounds. It has become a hot research topic to improve the anticancer activity of cisplatin via ligand substitution. Herein, the mono-substituent effect of superhalogens (SH), i.e. , X@B 12 N 12 (X = F, Cl, and Br) on the geometric structure, electronic properties, and hydrolysis of cisplatin has been detailedly studied by the density functional theory (DFT). Our results demonstrate that the newly formed Pt-N and Cl-B linkage bonds in the resulting cis -[Pt(NH 3 ) 2 (SH)Cl] (abbreviated as X-Pt ) complexes are strong polar covalent bonds, whereas the remaining Pt-Cl bonds are weakened in these cisplatin derivatives, which facilitates the hydrolysis of Cl – to generate active aquated species. Especially, it is found that F-Pt possesses the highest stability and the lowest total energy barrier for generating di-aquated species among these X-Pt compounds.