Synthesis, Characterization, and DNA Binding Properties of a Series of Ru, Pt Mixed-Metal Complexes

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• 作者：R. Lee Williams ; H. Nathaniel Toft ; Brenda Winkel ; and Karen J. Brewer
• 刊名：Inorganic Chemistry
• 出版年：2003
• 出版时间：July 14, 2003
• 年：2003
• 卷：42
• 期：14
• 页码：4394 - 4400
• 全文大小：132K
• 年卷期：v.42,no.14(July 14, 2003)
• ISSN：1520-510X

文摘

A series of mixed-metal complexes coupling ruthenium light absorbers to platinum reactive metal sites throughpolyazine bridging ligands have been prepared of the form [(tpy)RuCl(BL)PtCl₂](PF₆) (BL = 2,3-bis(2-pyridyl)pyrazine (dpp), 2,3-bis(2-pyridyl)quinoxaline (dpq), 2,3-bis(2-pyridyl)benzoquinoxaline (dpb); tpy = 2,2':6',2' '-terpyridine). These systems possess electron-rich Ru metal centers bound to five polyazine nitrogens and onechloride ligand. This leads to complexes with low-energy Ru BL charge-transfer bands that are tunable with BLvariation occurring at 544, 632, and 682 nm for dpp, dpq, and dpb, respectively. This tuning of the charge-transferenergy results from a stabilization of the BL(*) orbitals in this series as evidenced by the cathodic shift in the firstreduction of these complexes occurring at -0.50, -0.32, and -0.20 V vs Ag/AgCl, for dpp, dpq, and dpb, respectively.The chlorides bound to the Pt^II center are substitutionally labile giving these complexes the ability to covalentlybind to DNA. All three title bimetallics, [(tpy)RuCl(BL)PtCl₂](PF₆), avidly bind double-stranded DNA with t_1/2 = 1-2min, substantially reducing the migration of DNA through an agarose gel. Details of the synthetic methods, FABMS data, spectroscopic and electrochemical properties, and DNA binding studies are presented.