Novel arylplatinum complexes with 2,2′‐dimethyl‐4,4′‐bithiazole: Synthesis, characterization, single crystal structure determination, and investigation of CT‐DNA interaction

Abstract

Arylplatinum complexes containing 2,2′‐dimethyl‐4,4′‐bithiazole (a ligand with two different sulfur and nitrogen donor atoms, dm4bt) were synthesized by the reaction of [PtPh2(S (CH3)2)2] and [Pt(p‐CH3C6H4)2(S (CH3)2)2] with dm4bt in a 1:1 stoichiometry. In these heteroleptic platinum complexes, dm4bt was coordinated to the Pt centers as a chelating ligand using N2 donor atoms. The synthesized platinum(II) complexes were characterized by elemental analysis, conductometry, proton nuclear magnetic resonance (1H NMR), Fourier‐transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–Vis). The single crystal structure of the para‐tolyl platinum(II) complex, including dm4bt, was obtained by X‐ray crystallography. To investigate the interaction of DNA with the organoplatinum(II) complexes, different methods like fluorescence, absorption spectroscopy, and viscometry were employed. Furthermore, thermodynamic parameters such as entropy and enthalpy of the interaction between DNA and the complexes were calculated. According to the resulting positive entropy and enthalpy changes, it was demonstrated that the interaction originated from the hydrophobic forces.