Bifunctional Bioorganometallic Iridium(III)–Platinum(II) Complexes Incorporating Both Intercalative and Covalent DNA Binding Capabilities

Influence of the Polypyridyl (pp) Ligand Size on the DNA Binding Properties, Cytotoxicity and Cellular Uptake of Organoruthenium(II) Complexes of the Type [(η6‐C6Me6)Ru(L)(pp)]n+ [L = Cl, n = 1; L = (NH2)2CS, n = 2]

“…The compounds of the type [(η 6 -C 6 Me 6 )RuCl(pp)]-(CF 3 SO 3 ) 1-5 (pp = phen, tap, dpq, dppz, dppn) were prepared by refluxing the solvent complex [(η 6 …”

“…The preparation of [(η 6 -C 6 Me 6 )RuCl(phen)]Cl has recently been reported by Süss-Fink et al, [10] who studied the hydrolytic potential of the corresponding dicationic aqua complex [(η 6 -C 6 Me 6 )Ru(H 2 O)(phen)](BF 4 ) 2 for transfer hydrogenation reactions in aqueous solution. Both dppz and dppn have been confirmed as intercalating ligands in their Re I complexes such as [fac-Re(CO) 3 (pp)(pyridine)](CF 3 -SO 3 ), [11][12][13] which exhibit steric requirements similar to the half-sandwich polypyridyl (η 6 -C 6 Me 6 )Ru II complexes. As polypyridyl ligand intercalation and chloride substitution by purine nucleobases might be expected to compete as possible DNA binding modes for complexes 1-5, three thiourea complexes [(η 6 -C 6 Me 6 )Ru{(NH 2 ) 2 CS}(pp)] (CF 3 SO 3 ) 2 (pp = dpq, dppz, dppn) 6-8 were also investigated (Scheme 2).…”

“…To establish whether there is, indeed, an optimum polypyridyl ligand (pp) for side-on intercalation of (η 6 -C 6 Me 6 )-Ru II complexes, we have now studied the DNA binding 2+ into the G 1 T 2 /C 6 A 5 sequence of the hexanucleotide d(GTCGAC) 2 . [7] properties of compounds of the type [(η 6 -C 6 Me 6 )RuCl(pp)]-(CF 3 SO 3 ) 2 (1)(2)(3)(4)(5) with the diimine ligands phen (1,10-phenanthroline), tap (1,4,5,8-tetraazaphenanthrene), dpq (dipyrido[3,2-f:2Ј,3Ј-h]quinoxaline), dppz and dppn (Scheme 1).…”

“…[7] properties of compounds of the type [(η 6 -C 6 Me 6 )RuCl(pp)]-(CF 3 SO 3 ) 2 (1)(2)(3)(4)(5) with the diimine ligands phen (1,10-phenanthroline), tap (1,4,5,8-tetraazaphenanthrene), dpq (dipyrido[3,2-f:2Ј,3Ј-h]quinoxaline), dppz and dppn (Scheme 1). The preparation of [(η 6 -C 6 Me 6 )RuCl(phen)]Cl has recently been reported by Süss-Fink et al, [10] who studied the hydrolytic potential of the corresponding dicationic aqua complex [(η 6 -C 6 Me 6 )Ru(H 2 O)(phen)](BF 4 ) 2 for transfer hydrogenation reactions in aqueous solution. Both dppz and dppn have been confirmed as intercalating ligands in their Re I complexes such as [fac-Re(CO) 3 (pp)(pyridine)](CF 3 -SO 3 ), [11][12][13] which exhibit steric requirements similar to the half-sandwich polypyridyl (η 6 -C 6 Me 6 )Ru II complexes.…”

“…[1][2][3] We have recently established that organometallic half-sandwich compounds of the types [(η 5 -Cp*)Ir (amino acid-κS)(dppz)] n+ (n = 1-3, dppz = dipyrido[3,2-a:2Ј,3Ј-c]phenazine) [4][5][6] and [(η 6 -arene)Ru(amino acid-κS)(dppz)] n+ (n = 1-3, arene = C 6 H 6 , Me 3 C 6 H 3 , C 6 Me 6 ), [7] with a thioether-coordinated methionine-containing amino acid or peptide, exhibit strong intercalative binding into DNA. In these complexes and in [(η 5 -Cp*)Ru(dppz)(NO)] (CF 3 SO 3 ) 2 , [8] the magnitudes of the binding constants K b (8.8 ϫ 10 4 to 5.5 ϫ 10 6  -1 ) are clearly dependent on the overall cation charge n (1-3), i.e.…”