324765-53-9Relevant academic research and scientific papers
Ruthenium terpyridine complexes incorporating azo-imine based ancillary ligands. Synthesis, crystal structure, spectroelectrochemical properties and solution reactivities
Mondai, Biplab,Walawalkar, Mrinalini G.,Lahiri, Goutam Kumar
, p. 4209 - 4217 (2007/10/03)
Ruthenium terpyridine complexes of the type [RuII(trpy)(L)(X)][ClO4]n 1-15 [trpy = 2,2′ :6,2″-terpyridine; L = NC5H4N=NC6H4(R), R = H, m-Me, m-Cl, p-Me orp-Cl; X = Cl- n = 1 (1-5); H2O, n = 2 (6-10) or OH-, n = 1 (11-15)] have been synthesized. The single crystal structures of 1 and 6 were determined. Complex 4 develops in two possible isomeric forms whereas all other complexes stabilise preferentially in one isomeric form. The complexes exhibit strong MLCT bands near 500 nm and ligand based transitions in the UV region. 1-5 exhibit moderately strong emissions at 77 K near 600 nm. The chloro (1-5) and the hydroxo (11-15) complexes display ruthenium(m)-ruthenium(ii) couples and three to four successive one-electron ligand based reductions. The aqua-complexes (6-10) exhibit a reversible 2e-/2H+ single-step oxidation process in the pH range 1-5.5 corresponding to the [RuII(trpy)(L)(H2O)]2+-[Ru Iv(trpy)(L)(O)]2+ couple and the potential decreases linearly with increase in pH. The chemical oxidations of 6-10 by an excess of CeIV in 0.5 M H2SO4 also lead to the formation of corresponding [RuIV(trpy)(L)(O)]2+. The oxo-complexes are stable only in the presence of an excess of CeIV, otherwise they catalyse the oxidation of water to dioxygen and convert back into the parent aqua-species. The pseudo first order rate constant of the process [RuIV(trpy)(L)(O)]2+ → [RuII(trpy)(L)(H2O)]2+ has been determined. The Royal Society of Chemistry 2000.
