title: Trans-pyridine tetraammine complexes of RuII and RuIII with N7-coordinated purine nucleosides.
abstract: The synthesis, spectroscopic, and electrochemical properties of trans-[L(Pyr)(NH3)4RuII/III] (Pyr = py, 3-phpy, 4-phpy, 3-pnpy, or 4-bnpy; L = H2O, Guo, dGuo, 1MeGuo, Gua, Ino, or G7-DNA) are reported. As expected, the Pyr ligand slows DNA binding by trans-[(H2O)(Pyr)(NH3)4RuII]2+ relative to [(H2O)(NH3)5RuII]2+ and favors reduction of RuIII by about 150 mV. The pyridine ligand also promotes the disproportionation of RuIII to afford the corresponding complexes of RuII and, presumably, RuIV. For L = Ino, disproportionation follows the rate law: d[RuII]/dt = k0[RuIII] + k1[OH-][RuIII], k0 = (2.7 +/- 0.7) x 10(-4) s-1 and k1 = 70 +/- 1 M-1 s-1.
authors.affiliation: Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
authors.forename: M
authors.initials: M
authors.lastname: Zhao
authors.forename: M J
authors.initials: MJ
authors.lastname: Clarke
mesh_terms: D000588:Amines / Q000737:chemistry; D004563:Electrochemistry; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011684:Purine Nucleosides / Q000737:chemistry* / Q000378:metabolism; D011725:Pyridines / Q000737:chemistry* / Q000378:metabolism; D017975:Ruthenium Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000588:Amines; D011684:Purine Nucleosides; D011725:Pyridines; D017975:Ruthenium Compounds