Resonance Raman Probing of the Interaction between Dipyridophenazine Complexes of Ru(II) and DNA

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• 作者：Colin G. Coates ; Luc Jacquet ; John J. McGarvey ; Steven E. J. Bell ; Ala H. R. Al-Obaidi ; and John M. Kelly
• 刊名：Journal of the American Chemical Society
• 出版年：1997
• 出版时间：July 30, 1997
• 年：1997
• 卷：119
• 期：30
• 页码：7130 - 7136
• 全文大小：200K
• 年卷期：v.119,no.30(July 30, 1997)
• ISSN：1520-5126

文摘

Resonance Raman (RR) spectroscopy has been used to probe theinteraction between dipyridophenazine(dppz) complexes of ruthenium(II),[Ru(L)₂(dppz)]²⁺ (L = 1,10-phenanthroline(1) and 2,2-bipyridyl (2)), and calf-thymus DNA. Ground electronic state RR spectra at selected probewavelengths reveal enhancement patterns whichreflect perturbation of the dppz-centered electronic transitions in theUV-vis spectra in the presence of DNA.Comparison of the RR spectra recorded of the short-lived MLCTexcited states of both complexes in aqueous solutionwith those of the longer-lived states of the complexes in the DNAenvironment reveals changes to excited statemodes, suggesting perturbation of electronic transitions of the dppzligand in the excited state as a result of intercalation.The most prominent feature, at 1526 cm^-1, appears inthe spectra of both 1 and 2 and is a convenientmarker bandfor intercalation. For 1, the excited state studieshave been extended to the ges/gifchars/Delta.gif" BORDER=0 > and ges/entities/Lgr.gif"> enantiomers. The markerbandappears at the same frequency for both but with different relativeintensities. This is interpreted as reflecting thedistinctive response of the enantiomers to the chiral environment ofthe DNA binding sites. The results, togetherwith some analogous data for other potentially intercalating complexes,are considered in relation to the more generalapplication of time-resolved RR spectroscopy for investigation ofintercalative interactions of photoexcited metalcomplexes with DNA.