Halogenation of Tris(amido)tantalacarboranes with Dihalomethanes CH2X2 (X = Cl, Br)

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Title:Halogenation of Tris(amido)tantalacarboranes with Dihalomethanes CH2X2 (X = Cl, Br)
Creators:
Fox, Mark A.
Goeta, Andrés E.
Hughes, Andrew K.
Malget, John M.
Wade, Ken
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 67, 6, pp. 791-807
Uncontrolled Keywords:Isoelectronic analogues, Metallacarboranes, Halogenations, Tantalacarboranes, Tantalum, Carboranes

Abstract

Slow reactions of isomeric metallacarboranes of general formulae [(NMe<sub>2</sub>)<sub>3</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] (3&nbsp;isomers) and [(NMe<sub>2</sub>)<sub>3</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>10</sub>Me] (3 isomers) with CD<sub>2</sub>Cl<sub>2</sub> afford quantitative yields of&nbsp;monochloro complexes [Cl(NMe<sub>2</sub>)<sub>2</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] and [Cl(NMe<sub>2</sub>)<sub>2</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>10</sub>Me]. Exposure to&nbsp;CD<sub>2</sub>Cl<sub>2</sub> for months leads to solutions containing about 70% of the dichlorides in three cases. More prolonged exposure of these and the other monochlorides leads to a mixture of&nbsp;boron-substituted complexes. Hydrolysis of [3,3,3-(NMe<sub>2</sub>)<sub>3</sub>-3,1,2-TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] by moist toluene results in the formation of the oxo-bridged complex 3,3'-[3,3-(NMe<sub>2</sub>)<sub>2</sub>-3,1,2-TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]<sub>2</sub>(μ-O), characterised by single-crystal X-ray crystallography. The limited solubility of the latter complex in CD<sub>2</sub>Cl<sub>2</sub> eliminates the presence of this compound in the reaction of [3,3,3-(NMe<sub>2</sub>)<sub>3</sub>-3,1,2-TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] with CD<sub>2</sub>Cl<sub>2</sub>. The reaction of [2,2,2-(NMe<sub>2</sub>)<sub>3</sub>-2,1,12-TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] with CH<sub>2</sub>Br<sub>2</sub> in C<sub>6</sub>D<sub>6</sub> quantitatively yields the monobromide [2-Br-2,2-(NMe<sub>2</sub>)<sub>2</sub>-2,1,12-TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]. Prolonged reaction with CH<sub>2</sub>Br<sub>2</sub> leads directly to isomeric boron-substituted complexes with no evidence for dibromides. The influence on <sup>11</sup>B, <sup>13</sup>C and <sup>1</sup>H NMR chemical shifts of replacing an amide group in [(NMe<sub>2</sub>)<sub>3</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] with chloride to give [Cl(NMe<sub>2</sub>)<sub>2</sub>TaC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>] is also discussed. <p>

Title:Halogenation of Tris(amido)tantalacarboranes with Dihalomethanes CH2X2 (X = Cl, Br)
Creators:
Fox, Mark A.
Goeta, Andrés E.
Hughes, Andrew K.
Malget, John M.
Wade, Ken
Uncontrolled Keywords:Isoelectronic analogues, Metallacarboranes, Halogenations, Tantalacarboranes, Tantalum, Carboranes
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:67
Number:6
Page Range:pp. 791-807
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20020791UNSPECIFIED
ID Code:1955
Item Type:Article
Deposited On:06 Feb 2009 17:14
Last Modified:06 Feb 2009 16:14

Citation

Fox, Mark A.; Goeta, Andrés E.; Hughes, Andrew K.; Malget, John M.; Wade, Ken (2002) Halogenation of Tris(amido)tantalacarboranes with Dihalomethanes CH2X2 (X = Cl, Br). Collection of Czechoslovak Chemical Communications, 67 (6). pp. 791-807. ISSN 0010-0765

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