4 research outputs found
A biophysical study of the interactions of palladium(II), platinum(II) and gold(III) complexes of aminopyridyl-2,2â˛-bipyridine ligands with RNAs and other nucleic acid structures
Metals in Catalysis, Biomimetics & Inorganic Material
Induction of a FourâWay Junction Structure in the DNA Palindromic Hexanucleotide 5â˛âd(CGTACG)â3Ⲡby a Mononuclear Platinum Complex
Fourâway junctions (4WJs) are supramolecular DNA assemblies comprising four interacting DNA strands that in biology are involved in DNAâdamage repair. In this study, a new mononuclear platinum(II) complex 1 was prepared that is capable of driving the crystallization of the DNA oligomer 5â˛âd(CGTACG)â3Ⲡspecifically into a 4WJâlike motif. In the crystal structure of the 1âCGTACG adduct, the distortedâsquareâplanar platinum complex binds to the core of the 4WJâlike motif through ĎâĎ stacking and hydrogen bonding, without forming any platinumânitrogen coordination bonds. Our observations suggest that the specific molecular properties of the metal complex are crucially responsible for triggering the selective assembly of this peculiar DNA superstructure.Metals in Catalysis, Biomimetics & Inorganic Material
Photochemical Resolution of a Thermally Inert Cyclometalated Ru(phbpy)(NâN)(Sulfoxide)+ Complex
In this work a photosubstitution strategy is presented that can be used for the isolation of chiral organometallic complexes. A series of five cyclometalated complexes Ru(phbpy)(NâN)(DMSO-ÎşS)](PF6) ([1]PF6-[5]PF6) were synthesized and characterized, where Hphbpy = 6â˛-phenyl-2,2â˛-bipyridyl, and NâN = bpy (2,2â˛-bipyridine), phen (1,10-phenanthroline), dpq (pyrazino[2,3-f][1,10]phenanthroline), dppz (dipyrido[3,2-a:2â˛,3â˛-c]phenazine, or dppn (benzo[i]dipyrido[3,2-a,2â˛,3â˛-c]phenazine), respectively. Due to the asymmetry of the cyclometalated phbpyâ ligand, the corresponding [Ru(phbpy)(NâN)(DMSO-ÎşS)]+complexes are chiral. The exceptional thermal inertness of the RuâS bond made chiral resolution of these complexes by thermal ligand exchange impossible. However, photosubstitution by visible light irradiation in acetonitrile was possible for three of the five complexes ([1]PF6-[3]PF6). Further thermal coordination of the chiral sulfoxide (R)-methyl p-tolylsulfoxide to the photoproduct [Ru(phbpy)(phen)(NCMe)]PF6, followed by reverse phase HPLC, led to the separation and characterization of the two diastereoisomers of [Ru(phbpy)(phen)(MeSO(C7H7))]PF6, thus providing a new photochemical approach toward the synthesis of chiral cyclometalated ruthenium(II) complexes. Full photochemical, electrochemical, and frontier orbital characterization of the cyclometalated complexes [1]PF6-[5]PF6 was performed to explain why [4]PF6 and [5]PF6 are photochemically inert while [1]PF6-[3]PF6 perform selective photosubstitution.Metals in Catalysis, Biomimetics & Inorganic Material
A biophysical study of the interactions of palladium(II), platinum(II) and gold(III) complexes of aminopyridyl-2,2â˛-bipyridine ligands with RNAs and other nucleic acid structures
Metals in Catalysis, Biomimetics & Inorganic Material