Electrochemical Behaviour of trans-[FeH(CN)(dppe)2] Adducts

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Title:Electrochemical Behaviour of trans-[FeH(CN)(dppe)2] Adducts
Creators:
Almeida, Sílvia S. P. R.
Guedes Da Silva, M. Fátima C.
Pombeiro, Armando J. L.
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 68, 9, pp. 1663-1676
Uncontrolled Keywords:Heteronuclear complexes, Multinuclear complexes, Cyclic voltammetry, Transition metals, Redox-potential parameterisation, Electrochemistry, Bridging cyanide, Iron, Comproportionation constant

Abstract

Electrochemical behaviour of various metallo cyano adducts of <i>trans</i>-[FeH(CN)(dppe)<sub>2</sub>], <i>viz.</i> the dinuclear complexes [FeH(dppe)<sub>2</sub>(μ-CN)PdCl<sub>2</sub>(PPh<sub>3</sub>)], [FeH(dppe)<sub>2</sub>(μ-CN)NiCl<sub>2</sub>(PCy<sub>3</sub>)], and trinuclear [{FeH(dppe)<sub>2</sub>(μ-CN)}<sub>2</sub>(ReOCl<sub>3</sub>)], [{FeH(dppe)<sub>2</sub>(μ-CN)}<sub>2</sub>PtCl(Ph)] and [{FeX(dppe)<sub>2</sub>(μ-CN)}<sub>2</sub>WCl<sub>3</sub>(OH)] (X = Cl or OH, dppe = 1,2-diphenylphosphinoethane, PCy<sub>3</sub> = P(C<sub>6</sub>H<sub>11</sub>)<sub>3</sub>), as well as the benzoylisocyanide mononuclear adduct <i>trans</i>-[FeH(CNCOPh)- (dppe)<sub>2</sub>], is reported. All of them exhibit Fe<sup>II</sup>/Fe<sup>III</sup>-based oxidations (which are reversible, except for <i>trans</i>-[FeH(CNCOPh)(dppe)<sub>2</sub>]). The metallocyanide bridges C≡N-Re-N≡C and C≡N-W-N≡C in [{FeH(dppe)<sub>2</sub>(μ-CN)}<sub>2</sub>(ReOCl<sub>3</sub>)] and [{FeX(dppe)<sub>2</sub>(μ-CN)}<sub>2</sub>WCl<sub>3</sub>(OH)], respectively, allow electronic communication between the iron centres, with possible generation of mixed-valence Fe<sup>II</sup>/Fe<sup>III</sup> complexes whose comproportionation constant could be estimated in the former case. From the values of the measured oxidation potentials, the electrochemical <i>P</i><sub>L</sub> and <i>E</i><sub>L</sub> ligand parameters have been estimated for the metallocyanide ligands that were shown to behave as stronger net electron donors than organoisocyanides, although weaker than cyanide itself. Ligand-centred reduction processes were also observed to lead, in the cases of complexes <i>trans</i>-[FeH(CNCOPh)(dppe)<sub>2</sub>] (CNCOPh-based reduction) and [FeH(dppe)<sub>2</sub>(μ-CN)PdCl<sub>2</sub>(PPh<sub>3</sub>)] (Pd<sup>II</sup>-based reduction in the CNPdCl<sub>2</sub>(PPh<sub>3</sub>)<sup>-</sup> metallocyanide ligand), to the dissociation of the adduct, with regeneration of the parent cyano complex <i>trans</i>-[FeH(CN)(dppe)<sub>2</sub>], thus reflecting the reductive decrease of the electrophilic (or Lewis acidic) character of the benzoyl and {PdCl<sub>2</sub>(PPh<sub>3</sub>)} groups. <p>

Title:Electrochemical Behaviour of trans-[FeH(CN)(dppe)2] Adducts
Creators:
Almeida, Sílvia S. P. R.
Guedes Da Silva, M. Fátima C.
Pombeiro, Armando J. L.
Uncontrolled Keywords:Heteronuclear complexes, Multinuclear complexes, Cyclic voltammetry, Transition metals, Redox-potential parameterisation, Electrochemistry, Bridging cyanide, Iron, Comproportionation constant
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:68
Number:9
Page Range:pp. 1663-1676
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20031663UNSPECIFIED
ID Code:2145
Item Type:Article
Deposited On:06 Feb 2009 17:16
Last Modified:06 Feb 2009 16:16

Citation

Almeida, Sílvia S. P. R.; Guedes Da Silva, M. Fátima C.; Pombeiro, Armando J. L. (2003) Electrochemical Behaviour of trans-[FeH(CN)(dppe)2] Adducts. Collection of Czechoslovak Chemical Communications, 68 (9). pp. 1663-1676. ISSN 0010-0765

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