About Open Access
DNA Sequence and Ancillary Ligand Modulate the Biexponential Emission Decay of Intercalated [Ru(L)
Lookup NU author(s)
Dr Eimer Tuite
McKinley AW, Andersson J, Lincoln P, Tuite EM
Chemistry: A European Journal
15142 – 15150
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
The bi-exponential emission decay of [Ru(L)2dppz]2+ (L=N,N'-diimine ligand) bound to DNA has been studied as a function of polynucleotide sequence, enantiomer, and nature of L (phenanthroline vs. bipyridine). The lifetimes (ti) and pre-exponential factors (ai) depend on all three parameters. With [poly(dA-dT)]2, the variation of ai with [Nu]/[Ru] has little dependence on L for ?-[Ru(L)2dppz]2+ but a substantial dependence for ?-[Ru(L)2dppz]2+. With [poly(dG-dC)]2, by contrast, the ?-enantiomer ai values depend strongly on the nature of L, whereas those of the ?-enantiomer are relatively unaffected. DNA-bound linked dimers show similar photophysical behaviour. The lifetimes are identified with two geometries of minor-groove intercalated [Ru(L)2dppz]2+, resulting in differential water access to the phenazine nitrogen atoms. Interplay of cooperative and anti-cooperative binding resulting from complexcomplex and complexDNA interactions is responsible for the observed variations of ai with binding ratio. [Ru(phen)2dppz]2+ emission is quenched by guanosine in DMF, which may further rationalise the shorter lifetimes observed with guanine-rich DNA.
Wiley - V C H Verlag GmbH & Co. KGaA
Newcastle University Library, NE2 4HQ, United Kingdom. Tel: 0044 (191) 222 7657
©2014 Newcastle University Library