Spectroelectrochemical behaviour of the trinuclear [Ru3O(O2CCH3)6(isonicotinamide)3] cluster

1989 ◽  
Vol 67 (10) ◽  
pp. 1632-1635 ◽  
Author(s):  
Henrique E. Toma ◽  
Carlos J. Cunha
Keyword(s):  
Oxidation States ◽  
Metal Charge ◽  
Trinuclear Cluster ◽  
Oxygen Ion ◽  
Redox Couples ◽  
Metal Metal ◽  
Charge Transfer Transitions ◽  
Central Oxygen ◽  
Acetonitrile Solutions ◽  
Metal Charge Transfer

The [Ru3O(OOCCH3)6(isonicotinamide)3] cluster exhibits reversible electrochemical and spectroelectrochemical behaviour in acetonitrile solutions, associated with a series of successive μ-oxo RuIVRuIVRuIII/RuIVRu1IIRuIII/…/RuIIRuIIRuII redox couples with E0 = 2.16, 1.21, 0.19, −0.98, and −1.4 V versus SHE. The metal-isonicotinamide and metal–metal charge–transfer transitions shift to lower energies as the oxidation states of the ruthenium ions decrease. In alkaline aqueous solution, the μ-oxo RuIIIRuIIIRuII cluster can be reversibly reduced to the μ-oxo RuIIIRuIIRuII product (E0 = −0.85 V); however, below pH 4, the reduction proceeds according to two successive steps, yielding RIIIRIIRuII species with loss of the central oxygen ion. These species can be reoxidized in the reverse potential scan, regenerating the µ-oxo RuIIIRuIIIRuII complex. Keywords: ruthenium–acetate clusters, cluster spectroelectrochemistry, cluster electrochemistry, ruthenium–isonicotinamide complex, trinuclear cluster.

Metal–metal charge transfer and solvatochromism in cyanomanganese carbonyl complexes of ruthenium and osmium

2006 ◽  
pp. 3584-3596 ◽  
Author(s):  
Christopher J. Adams ◽  
Neil G. Connelly ◽  
Nicholas J. Goodwin ◽  
Owen D. Hayward ◽  
A. Guy Orpen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Carbonyl Complexes ◽  
Metal Charge ◽  
Metal Metal ◽  
Metal Charge Transfer

Macrocyclic Thiophene-Appended Cyanido-Bridged CoIII/FeII Complexes: Precursors to Mixed-valent Poly-thiophene Hybrid Materials

2009 ◽  
Vol 62 (10) ◽  
pp. 1214 ◽  
Author(s):  
Sharizal Hasan ◽  
Nathan L. Kilah ◽  
Manuel Martinez ◽  
Paul V. Bernhardt
Keyword(s):  
Hybrid Materials ◽  
Transition Metal Ions ◽  
Spectroscopic Properties ◽  
Trinuclear Complex ◽  
Metal Charge ◽  
Trinuclear Complexes ◽  
Redox Active ◽  
Charge Transfer Transitions ◽  
Active Transition ◽  
Metal Charge Transfer

The new cyanido-bridged mixed valent FeII/CoIII macrocyclic complexes [L2CoIII(μ-NC)FeII(CN)5]– and trans-[L2CoIII(μ-NC)FeII(CN)4(μ-CN)CoIIIL2]2+ have been prepared and characterized spectroscopically. The trinuclear complex trans-[L2Co(μ-NC)Fe(CN)4(μ-CN)CoL2](ClO4)2·11H2O has been characterized crystallographically. The di- and trinuclear complexes exhibit metal-to-metal charge transfer transitions characteristic of Class II mixed valent chromophores and their redox and spectroscopic properties have been analyzed by Hush theory. The thiophene group attached to the macrocycle L2 in these complexes may serve as a precursor to conducting polythiophene-based hybrid materials incorporating redox active transition metal ions.

scholarly journals Photoredox Reactions of Hg(CN)2/[Fe(CN)6]4- and [HgCo2(CN)10]6- Induced by Inner-Sphere Metal to Metal Charge Transfer Excitation

1989 ◽  
Vol 44 (2) ◽  
pp. 145-148 ◽  
Author(s):  
H. Kunkely ◽  
G. Stochel ◽  
A. Vogler
Keyword(s):  
Charge Transfer ◽  
Aqueous Mixtures ◽  
Strongly Coupled ◽  
Metal Charge ◽  
Weakly Coupled ◽  
Metal Metal ◽  
Inner Sphere ◽  
Charge Transfer Excitation ◽  
Metal Bonds ◽  
Metal Charge Transfer

Abstract Incomplexes of the type [(NC)2HgIIN CFeII(CN)5]4- which are formed in aqueous mixtures of Hg(CN)2 and [Fe(CN)6]4- both metals are weakly coupled. Optical metal to metal charge transfer (MMCT) excitation from FeII to HgIIleads to the reduction of HgII to Hg0 an the oxidation of [Fe(CN)6]4- to [Fe(CN)6]3-. In the complex [(NC)5CoI-HgII-CoI(CN)5]6- the m etals are strongly coupled by direct but polar metal metal bonds. MMCT (CoI ￫ HgII) excitation induces the photoredox reaction: [HgCo2(CN)10]6-￫Hg0 + 2[Co(CN)5]3-.

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