Influence of Metal Core Composition on Redox Properties and Photoreactivity of the Clusters [H4-xRu4-xRhx(CO)12] (x = 0, 2, 3, 4)

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Title:Influence of Metal Core Composition on Redox Properties and Photoreactivity of the Clusters [H4-xRu4-xRhx(CO)12] (x = 0, 2, 3, 4)
Creators:
Bakker, Maarten J.
Pakkanen, Tapani A.
Hartl, František
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 66, 7, pp. 1062-1077
Uncontrolled Keywords:Photochemistry, Carbonyl complexes, Redox properties, Rhodium, Hydrides, Electrochemistry, IR spectroscopy, Ruthenium, Spectroelectrochemistry, Mixed-metal clusters

Abstract

Electrochemical properties of tetrahedral clusters [H<sub>2</sub>Ru<sub>2</sub>Rh<sub>2</sub>(CO)<sub>12</sub>], [HRuRh<sub>3</sub>(CO)<sub>12</sub>] and [Rh<sub>4</sub>(CO)<sub>12</sub>] were investigated in order to evaluate the influence of metal core composition in the series [H<sub>4-<i>x</sub></i>Ru<sub>4-<i>x</sub></i>Rh<i><sub>x</sub></i>(CO)<sub>12</sub>] (<i>x</i> = 0-4). The cluster [H<sub>3</sub>Ru<sub>3</sub>Rh(CO)<sub>12</sub>] was not available in sufficient quantities. As reported for [H<sub>4</sub>Ru<sub>4</sub>(CO)<sub>12</sub>], electrochemical reduction of the hydride-containing clusters [H<sub>2</sub>Ru<sub>2</sub>Rh<sub>2</sub>(CO)<sub>12</sub>] and [HRuRh<sub>3</sub>(CO)<sub>12</sub>] also results in (stepwise) loss of hydrogen, producing the anions [HRu<sub>2</sub>Rh<sub>2</sub>(CO)<sub>12</sub>]<sup>-</sup>, [Ru<sub>2</sub>Rh<sub>2</sub>(CO)<sub>12</sub>]<sup>2-</sup> and [RuRh<sub>3</sub>(CO)<sub>12</sub>]<sup>-</sup>. These anions can also be prepared from the neutral parent clusters <i>via</i> chemical routes. Electrochemical reduction of [Rh<sub>4</sub>(CO)<sub>12</sub>] does not result in the formation of any stable tetranuclear anion. Instead, [Rh<sub>5</sub>(CO)<sub>15</sub>]<sup>-</sup> and [Rh<sub>6</sub>(CO)<sub>15</sub>]<sup>2-</sup> are the major reduction products detected in the course of IR spectroelectrochemical experiments. Most likely, these cluster species are formed from the secondary CO-loss product [Rh<sub>4</sub>(CO)<sub>11</sub>]<sup>2-</sup> by fast redox condensation reactions. Their reoxidation regenerates parent [Rh<sub>4</sub>(CO)<sub>12</sub>], together with some [Rh<sub>6</sub>(CO)<sub>16</sub>]. Unlike [H<sub>4</sub>Ru<sub>4</sub>(CO)<sub>12</sub>] that undergoes photochemical CO-dissociation, [H<sub>2</sub>Ru<sub>2</sub>Rh<sub>2</sub>(CO)<sub>12</sub>] and [Rh<sub>4</sub>(CO)<sub>12</sub>] are completely photostable in neat hexane and dichloromethane as well as in the presence of oct-1-ene. <p>

Title:Influence of Metal Core Composition on Redox Properties and Photoreactivity of the Clusters [H4-xRu4-xRhx(CO)12] (x = 0, 2, 3, 4)
Creators:
Bakker, Maarten J.
Pakkanen, Tapani A.
Hartl, František
Uncontrolled Keywords:Photochemistry, Carbonyl complexes, Redox properties, Rhodium, Hydrides, Electrochemistry, IR spectroscopy, Ruthenium, Spectroelectrochemistry, Mixed-metal clusters
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:66
Number:7
Page Range:pp. 1062-1077
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20011062UNSPECIFIED
ID Code:1843
Item Type:Article
Deposited On:06 Feb 2009 17:13
Last Modified:06 Feb 2009 16:13

Citation

Bakker, Maarten J.; Pakkanen, Tapani A.; Hartl, František (2001) Influence of Metal Core Composition on Redox Properties and Photoreactivity of the Clusters [H4-xRu4-xRhx(CO)12] (x = 0, 2, 3, 4). Collection of Czechoslovak Chemical Communications, 66 (7). pp. 1062-1077. ISSN 0010-0765

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