Picosecond Kerr-gated time-resolved resonance Raman spectroscopy of the Ru(phen)(2)dppz (2+) interaction with DNA
2002 (English)In: Journal of Inorganic Biochemistry, ISSN 0162-0134, E-ISSN 1873-3344, Vol. 91, no 1, 286-297 p.Article in journal (Refereed) Published
To investigate the basis of the 'light-switch' effect, the solvent dependence of the Kerr-gated picosecond-time resolved resonance Raman (TR3) spectra of [Ru(bpy),dppz](2+), [Ru(phen)(2)dppz](2+), and the modified complex [Ru(phen)(2)cpdppzOMe](2+) and a dimer [mu-C4(cpdppz)(2)-(phen)(4)Ru-2](4+) were studied. The investigation focussed on comparing the behaviour of [Ru(phen)(2)dppz](2+) in acetonitrile, ethanol, H2O, D2O, and DNA. The data are consistent with a model wherein excitation induces metal-to-ligand charge transfer (MLCT) to any of the ligands (termed the 'precursor' state) which, by interligand electron transfer (ILET), produces an excited state localised on the dppz ligand, MLCT1. In water this state relaxes with a characteristic time of similar to6 ps to a non-emissive state (MLCT2). The TR3 spectra in water, acetonitrile and DNA are all distinctly different. However. the early (4 ps) water spectrum resembles the spectrum in DNA. This interesting observation suggests that the DNA-bound excited state of the complex can be thought of as a model for the initial, poorly solvated state in water.
Place, publisher, year, edition, pages
2002. Vol. 91, no 1, 286-297 p.
time resolved resonance Raman (TR3) spectroscopy, ruthenium, dipyridophenazine, DNA, metal-to-ligand charge transfer (MLCT), interligand electron-transfer, molecular light switch, transfer excited-state, ruthenium(ii) complexes, charge-transfer, dipyridophenazine complexes, dynamics, binding, ligand, localization
IdentifiersURN: urn:nbn:se:kth:diva-21765ISI: 000177141500033OAI: oai:DiVA.org:kth-21765DiVA: diva2:340463
QC 201005252010-08-102010-08-10Bibliographically approved