Photoadducts of Metallic Compounds with Nucleic Acids − Role Played by the Photoelectron Transfer Process and by the TAP and HAT Ligands in the Ru^II Complexes

Abstract

The properties that are characteristic of TAP (1,4,5,8-tetraazaphenanthrene) and HAT (1,4,5,8,9,12-hexaazatriphenylene) Ru II complexes under illumination are highlighted and compared with those of other metallic complexes. In particular, the photo-oxidizing power of their 3 MLCT states leads to a quenching of luminescence accompanied by a photoreaction when they are in presence of nucleic acids. The proton-

Ru–TAP complexes and DNA: from photo-induced electron transfer to gene photo-silencing in living cells

“…The formation of bi-adducts was first discovered with another complex, [Ru(HAT) 2 phen] 2+ (HAT = 1,4,5,8,9,12-hexaazatriphenylene) (figure 3a) [32]. This compound behaves in the same way as the Ru-TAP complexes, thus also leading to a PET process and adduct formation.…”

“…In order to demonstrate unambiguously the formation of a bi-adduct via the occurrence of photo-cross-linking between two G-containing oligonucleotides, three types of photo-oxidizing Ru complexes have been tested [35] [32] indicates that it interacts less efficiently with DNA than complexes containing a classical intercalating ligand such as dppz or PHEHAT. Viscosity measurements with CT-DNA indicate that [Ru(HAT) 2 phen] 2+ induces an increase in viscosity that is slightly lower than that with ethidium bromide [34], and its retention of emission polarization anisotropy in the presence of DNA is significantly lower than that for a classical metallo-intercalator [35].…”

Interaction and Binding Modes of bis-Ruthenium(II) Complex to Synthetic DNAs

“…In addition to a variety of binding modes, metal complexes also show distinctive chemical activities. They can coordinate directly to DNA Lewis base sites and undergo redox reactions with DNA or generate reactive oxygen containing species (an attribute particularly relevant to photodynamic therapy, PDT) [2][3][4][5]. The ability to bind and to cleave DNA and interfere with the essential interaction of various transition metal complexes with DNA have been the subject of intense study due to their unique physical properties and potential applications in biology [6][7][8][9][10][11][12].…”

Synthesis, Structure, DNA‐Binding Properties, and Cytotoxicity of Ruthenium(II) Polypyridyl Complexes

“…The pattern (5) 95. 25(14) N(6)ÀRuÀC (38) 128.8(3) N(4)ÀRuÀN (6) 174.19 (13) was common to the most d 6 -metal polypyridyl complexes where the redox orbitals are localized on the individual ligands [36], and the data are compiled in Table 3. Complexes 1 and 2 exhibited one reversible oxidation at þ 1.35 and þ 1.31 V (vs. SCE), respectively, which is smaller than that of [Ru(phen) 3 ] 2 þ (1.40 V) [37].…”