Photophysics of Polyazaaromatic Ruthenium(II) Complexes Interacting with DNA

Photoreaction of [Ru(hat)2phen]2+ with Guanosine‐5′‐Monophosphate and DNA: Formation of New Types of Photoadducts

“…This could be due as demonstrated below to a better interaction of [Ru(hat) 2 phen] 2 + with CT-DNA. The luminescence quenching contrasts the luminescence enhancement of [Ru(hat) 2 phen] 2 + in the presence of [poly(dA-dT)] 2 up to a plateau value of 1.84 due to i) a protection of the luminophore by the polynucleotide from H 2 O or O 2 [29] and ii) the absence of quenching because [Ru(hat) 2phen] 2 + in the excited state cannot oxidise adenine or thymine units. A higher plateau value is reached in the case of [Ru(hat) 2 phen] 2 + than for the TAP complexes [4,13,28] because of a better protection of excited [Ru(hat) 2 phen] 2 + by the polynucleotide.…”

Mixed-ligand complexes of ruthenium(II) incorporating a diazo ligand: Synthesis, characterization and DNA binding

“…1 Ruthenium polypyridyl complexes have been extensively studied in this context as their luminescence and photochemical reactivity make them exceptionally versatile as probes of DNA structures. [2][3][4][5][6][7][8] These complexes bind to DNA by non-covalent interactions such as electrostatic binding, groove binding, intercalative binding and partial intercalative binding. 9 Barton et al have pioneered the application of chiral transition-metal polypyridyl complexes to probe local variations in double-helical DNA structures and their role in gene expression, [9][10][11][12][13] and have recently reported the mismatch recognition agent [Rh(bpy) 2 (chrysi)] 3+ (chrysi = 5,6-chrysenequinone diimine) that binds mismatch sites in DNA specifically and upon photoactivation cleaves the DNA backbone neighbouring the mismatch site.…”

Ru-Labeled Oligonucleotides for Photoinduced Reactions on Targeted DNA Guanines

“…The intensity decrease observed on each side of the denaturation temperature range may be attributed to the photophysics of [Ru(tap) 2 (dip)] 2 as a function of temperature. Indeed, a thermally activated crossing from the 3 MLCT state to the 3 MC (metal-centered) state [44,45] is responsible for the decrease in emission with enhanced temperature. [46] Moreover, the fact that the denaturation temperature derived from absorption measurements at 260 nm ( Figure 5) is the same as that measured from luminescence data (Figure 6, bottom) indicates clearly that the luminescence quenching may be attributed to the hybrid- Figure 6.…”