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

• Published in: Inorganica Chimica Acta Vol. 368; no. 1; pp. 252 - 256
• Main Authors: Hodges, Ashley S., Lee, Suk (Christy) Y., Hardcastle, Kenneth I., Saadein, M. Reza, Eichler, Jack F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-03-2011
• Subjects: Anticancer; Di-2-pyridyl ligands; DNA binding; Gold(III); Metallotherapy; methylbipy; Gold(III); LMCT; DPO; Metallotherapy; DPS; pyz-CH2-pyr; Anticancer; DPK; DNA binding; Di-2-pyridyl ligands
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2010.12.052

The synthesis of gold(III) complexes possessing three different classes of di-2-pyridyl ligands is reported. The di-2-pyridyl sulfide ligand coordinates gold(III) in a bidentate fashion, and forms a complex ion possessing a AuCl4− counterion; the di-2-pyridyl ketone ligand did not coordinate directly to the gold(III) metal center; and the di-2-pyridyl ether ligand formed a neutral complex in which the ligand binds to gold(III) in a monodentate fashion. [Display omitted]
► Di-2-pyridyl ligands linked by different groups exhibited varying coordination to gold(III). ► Di-2-pyridyl sulfide (DPS) (3) exhibited bidentate binding to gold(III). ► Di-2-pyridyl ether (DPO) (4) formed a neutral monodentate coordination complex with gold(III). ► Attempts to make gold(III) complexes with di-2-pyridyl ketone (DPK) (5) were unsuccessful. ► The coordination environments of compounds 3–5 were confirmed by X-ray crystallography.
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.