title: The triruthenium complex [[(acac)2Ru(II)]3(L)] containing a conjugated diquinoxaline[2,3-a:2',3'-c]phenazine (L) bridge and acetylacetonate (acac) as ancillary ligands. Synthesis, spectroelectrochemical and EPR investigation.
abstract: The compound [[(acac)2Ru]3(L)] (1) undergoes three well-separated one-electron oxidation and reduction processes. The EPR results indicate electron removal from the ruthenium(II) centres on oxidation and the occupation of a largely L-based molecular orbital on reduction. In spite of well-separated (DeltaE > or = 340 mV) oxidation no obvious intervalence charge transfer bands were detected in the Vis, NIR or IR regions, suggesting very weak electronic coupling between the metal centres in the mixed-valent intermediates 1+ and 1(2+). The separated (DeltaE > or = 540 mV) stepwise reduction produces weak near-infrared features associated with partially occupied pi* orbitals of L, the unusually high g anisotropy in the EPR spectrum of 1- is attributed to the occupation of a degenerate MO by the unpaired electron.
authors.affiliation: Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai.
authors.forename: Srikanta
authors.initials: S
authors.lastname: Patra
authors.forename: Biprajit
authors.initials: B
authors.lastname: Sarkar
authors.forename: Sandeep
authors.initials: S
authors.lastname: Ghumaan
authors.forename: Jan
authors.initials: J
authors.lastname: Fiedler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kaim
authors.forename: Goutam Kumar
authors.initials: GK
authors.lastname: Lahiri