Synthesis and/or molecular structures of some simple 2,1,7- and 2,1,12-ruthena- and cobaltacarboranes

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Title:Synthesis and/or molecular structures of some simple 2,1,7- and 2,1,12-ruthena- and cobaltacarboranes
Creators:
Lopez, Maria Elena
Ellis, David
Murray, Paul R.
Rosair, Georgina M.
Welch, Alan J.
Yellowlees, Lesley J.
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 75, 8, pp. 853-869
Uncontrolled Keywords:Crystallography, Metallacarboranes, Cobalt, X-Ray diffraction, Carboranes, Ruthenium, Electrochemistry, Boron clusters

Abstract

The ruthenacarboranes 2-(<i>p</i>-cymene)-2,1,7-<i>closo</i>-RuC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> (<b>2</b>) (<i>p</i>-cymene = 1-methyl-4-isopropylbenzene) and 2-(<i>p</i>-cymene)-2,1,12-<i>closo</i>-RuC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> (<b>3</b>) have been synthesised by simple metallation of [7,9-<i>nido</i>-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]<sup>2–</sup> and [2,9-<i>nido</i>-C2B<sub>9</sub>H<sub>11</sub>]<sup>2–</sup>, respectively. In preparing the known cobaltacarborane 2-(η-C5H<sub>5</sub>)-2,1,12-<i>closo</i>-CoC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> (<b>6</b>), the new bis(dicarbollide) [2,2′-Co(1,12-<i>closo</i>-C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>]<sup>–</sup> (as its [(η-C5H<sub>5</sub>)<sub>2</sub>Co]<sup>+</sup> salt; <b>7</b>) was also formed. Molecular structures of <b>2</b>, <b>3</b>, <b>6</b> and <b>7</b> and that of the known compound 2-(η-C5H<sub>5</sub>)-2,1,7-<i>closo</i>-CoC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> (<b>5</b>) have been determined. Patterns in 〈δ(<sup>11</sup>B)〉, the weighted average <sup>11</sup>B NMR chemical shift, of these metallacarboranes, together with those in 3-(<i>p</i>-cymene)-3,1,2-<i>closo</i>-RuC2B<sub>9</sub>H<sub>11</sub> (<b>1</b>) and 3-(η-C<sub>5</sub>H<sub>5</sub>)-3,1,2-<i>closo</i>-CoC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> (<b>4</b>) are discussed in relation to 〈δ(<sup>11</sup>B)〉 in the parent carboranes 1,2-<i>closo</i>-C2B<sub>10</sub>H<sub>12</sub>, 1,7-<i>closo</i>-C<sub>2</sub>B<sub>10</sub>H<sub>12</sub> and 1,12-<i>closo</i>-C<sub>2</sub>B<sub>10</sub>H<sub>12</sub>. The similarity between the <sup>1</sup>H and <sup>11</sup>B spectra of <b>6</b> and <b>7</b> confirm the isolobality of the [C5H<sub>5</sub>]<sup>–</sup> and [C2B<sub>9</sub>H<sub>11</sub>]<sup>2–</sup> ligands. An electrochemical study of <b>7</b> confirms that trends in the potential of the Co<sup>III</sup>/Co<sup>II</sup> couple for the series of isomers of (η-C5H<sub>5</sub>)CoC<sub>2</sub>B<sub>9</sub>H<sub>11</sub> are reproduced for the bis(dicarbollides) [Co(C<sub>2</sub>B<sub>9</sub>H<sub>11</sub>)<sub>2</sub>]<sup>–</sup>. The molecular structures of compounds <b>1</b>–<b>3</b> as a family and <b>4</b>–<b>6</b> as a family provide a unique opportunity to consider structural patterns in simple isomeric metallacarboranes.

Title:Synthesis and/or molecular structures of some simple 2,1,7- and 2,1,12-ruthena- and cobaltacarboranes
Creators:
Lopez, Maria Elena
Ellis, David
Murray, Paul R.
Rosair, Georgina M.
Welch, Alan J.
Yellowlees, Lesley J.
Uncontrolled Keywords:Crystallography, Metallacarboranes, Cobalt, X-Ray diffraction, Carboranes, Ruthenium, Electrochemistry, Boron 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:75
Number:8
Page Range:pp. 853-869
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc2010063UNSPECIFIED
ID Code:6195
Item Type:Article
Deposited On:11 Oct 2010 15:42
Last Modified:11 Oct 2010 13:43

Citation

Lopez, Maria Elena; Ellis, David; Murray, Paul R.; Rosair, Georgina M.; Welch, Alan J.; Yellowlees, Lesley J. (2010) Synthesis and/or molecular structures of some simple 2,1,7- and 2,1,12-ruthena- and cobaltacarboranes. Collection of Czechoslovak Chemical Communications, 75 (8). pp. 853-869.

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