[(Ph)<sub>3</sub>PBr][Br<sub>7</sub>], [(Bz)(Ph)<sub>3</sub>P]<sub>2</sub>[Br<sub>8</sub>], [(<i>n</i>-Bu)<sub>3</sub>MeN]<sub>2</sub>[Br<sub>20</sub>], [C<sub>4</sub>MPyr]<sub>2</sub>[Br<sub>20</sub>], and [(Ph)<sub>3</sub>PCl]<sub>2</sub>[Cl<sub>2</sub>I<sub>14</sub>]: Extending the Horizon of Polyhalides via Synthesis in Ionic Liquids
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Abstract
The five polyhalides [(Ph)<sub>3</sub>PBr][Br<sub>7</sub>], [(Bz)(Ph)<sub>3</sub>P]<sub>2</sub>[Br<sub>8</sub>], [(<i>n</i>-Bu)<sub>3</sub>MeN]<sub>2</sub>[Br<sub>20</sub>], [C<sub>4</sub>MPyr]<sub>2</sub>[Br<sub>20</sub>] ([C<sub>4</sub>MPyr] = <i>N</i>-butyl-<i>N</i>-methylpyrrolidinium), and [(Ph)<sub>3</sub>PCl]<sub>2</sub>[Cl<sub>2</sub>I<sub>14</sub>] were prepared by the reaction of dibromine and iodine monochloride in ionic liquids. The compounds [(Ph)<sub>3</sub>PBr][Br<sub>7</sub>] and [(Bz)(Ph)<sub>3</sub>P]<sub>2</sub>[Br<sub>8</sub>] contain discrete pyramidal [Br<sub>7</sub>]<sup>−</sup> and Z-shaped [Br<sub>8</sub>]<sup>2–</sup> polybromide anions. [(<i>n</i>-Bu)<sub>3</sub>MeN]<sub>2</sub>[Br<sub>20</sub>] and [C<sub>4</sub>MPyr]<sub>2</sub>[Br<sub>20</sub>] exhibit new infinite two- and three-dimensional polybromide networks and contain the highest percentage of dibromine ever observed in a compound. [(Ph)<sub>3</sub>PCl]<sub>2</sub>[Cl<sub>2</sub>I<sub>14</sub>] also consists of a three-dimensional network and is the first example of an infinite polyiodine chloride. All compounds were obtained from ionic liquids as the solvent that, on the one hand, guarantees for a high stability against strongly oxidizing Br<sub>2</sub> and ICl and that, on the other hand, reduces the high volatility of the molecular halogens
