title: Synthesis, potentiometric titration, electrochemical investigation and biological properties of trans-[RuCl2(dinic)4] (dinic = 3,5-pyridinecarboxylic acid).
abstract: This work discusses both the synthesis of trans-[RuCl2(dinic)4], dinic = 3,5-pyridinecarboxylic acid, and its main characteristics including potentiometric titration, spectroscopic and electrochemical properties, and some biological properties. The complex was synthesized using ruthenium blue solution as the precursor in a synthetic route. The complex was characterized using electronic spectroscopy, vibrational FT-IR spectroscopy, and Raman spectroscopy, as well as 1H and 13C NMR. The results indicated that the complex exhibits a trans-geometry. Cyclic voltammetry carried out in water:acetone 1:1 solution revealed a quasi-reversible process centered on the Ru(II) atom, as well as a dependence of the redox potential, E1/2, on pH. An analysis of the electronic spectra revealed that the MLCT (metal ligand charge transfer) band underwent a hypsochromic shift as the pH increased. Spectroelectrochemical analysis indicated that the visible region band progressively faded out upon oxidation. The equilibrium constants for the eight protons of the complex were determined by potentiometric titration. The complex neither inhibits the activity of nitrogen monoxide synthase nor acts as a scavenger for nitrogen monoxide. Nevertheless, the complex shows antinociceptive properties and acts as a scavenger for hydroxyl radicals.
authors.affiliation: Departamentos de Química, Universidade Federal de Santa Catarina UFSC, Florianópolis, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Seifriz
authors.forename: M
authors.initials: M
authors.lastname: Konzen
authors.forename: M M
authors.initials: MM
authors.lastname: Paula
authors.forename: N S
authors.initials: NS
authors.lastname: Gonçalves
authors.forename: B
authors.initials: B
authors.lastname: Spoganickz
authors.forename: T B
authors.initials: TB
authors.lastname: Creczynski-Pasa
authors.forename: V R
authors.initials: VR
authors.lastname: Bonetti
authors.forename: A
authors.initials: A
authors.lastname: Beirith
authors.forename: J B
authors.initials: JB
authors.lastname: Calixto
authors.forename: C V
authors.initials: CV
authors.lastname: Franco
mesh_terms: D000700:Analgesics / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D004563:Electrochemistry; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D009539:Nicotinic Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011199:Potentiometry; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D000700:Analgesics; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D009539:Nicotinic Acids; D009942:Organometallic Compounds; C403903:dichlorotetrakis(3,5-pyridinedicarboxylic acid)ruthenium(II); D019001:Nitric Oxide Synthase