Transient Resonance Raman Studies of Ru(II) Complexes in DNA and in Homogeneous Media

Autor: Colin G. Coates, John J. McGarvey, Johannes G. Vos, John M. Kelly, Luc Jacquet, Steven E. J. Bell, Tia E. Keyes
Rok vydání: 1999
Předmět:
Zdroj: Laser Chemistry. 19:237-243
ISSN: 1476-3516
0278-6273
Popis: Transient resonance Raman (TR2) spectroscopy has been used to investigate the metalligand charge-transfer (MLCT) excited states of Ru(II) polypyridyl complexes inDNAand in homogeneous solution. In DNA, complexes of the type [Ru(L)2(L′)]2+ were studied, where L=2, 2’-bipyridyl (bpy), 1,4, 5, 8-tetraazaphenanthrene (tap), and L′ dipyrido [3,2:a-2′ ,3′:c]-phenazine (dppz) or 1,4,5,8,9,12-hexaazatriphenylene (HAT). For [Ru(bpy)2(HAT)]2+, the enhancement pattern of vibrational modes in the TR2 spectra attributable to reduced HAT⋅− in the triplet MLCT state suggest perturbations to the intraligand transition of HAT⋅− in the presence of DNA. Transient RR spectra for [Ru(tap)2(dppz)]2+ are indicative of formation of the species RunII(tap⋅−)(tap)(dppz) by electron transfer from DNA to the triplet MLCT state of the complex.TR2 spectra for complexes of the type, [(Ru(bpy)2)n(L)]2+ , n=1, 2 where L=a triazole bridging ligand, illustrate the use of the technique as a probe of the response of MLCT states to the electronic environment.
Databáze: OpenAIRE
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