A report describing the effect of di-2-pyridyl ligand architecture on the coordination properties with gold(III)

In an effort to develop novel gold-based chemotherapies, gold(III) coordination complexes possessing a series of di-2-pyridyl ligands were targeted as synthetic products. It was found that di-2-pyridyl ligands linked by different groups exhibited varying coordination to gold(III). Di-2-pyridyl sulfide (DPS) exhibited bidentate binding to gold(III), and formed a complex ion with a gold tetrachloride counter ion {[(DPS)AuCl2]AuCl4; compound 3}; di-2-pyridyl ether (DPO) formed a neutral monodentate coordination complex with gold(III) {[(DPO)(AuCl3)]; compound 4}; and attempts to make a gold(III) complex with di-2-pyridyl ketone (DPK) were unsuccessful, as a complex ion possessing the protonated ligand and a gold tetrachloride anion was isolated {[HDPK][AuCl4]; compound 5}. Compounds 3–5 were structurally characterized using X-ray crystallography, which confirmed the different coordination environments around the gold(III) metal centers.