The reactivity of pentaphosphorus cations [P<sub>5</sub>R<sub>2</sub>]<sup>+</sup> (R = Cy, <i>i</i>Pr, Mes) cations with cyclopentadienyliron, -cobalt and -nickel complexes has been investigated. Reaction of [Cp<sup>Ar</sup>Fe(<i>µ</i>-Br)]<sub>2</sub> (Cp<sup>Ar</sup> = C<sub>5</sub>(C<sub>6</sub>H<sub>4</sub>-4-Et)<sub>5</sub>) with [P<sub>5</sub>R<sub>2</sub>][GaCl<sub>4</sub>] (R = <i>i</i>Pr and 2,4,6-Me<sub>3</sub>C<sub>6</sub>H<sub>2</sub> (Mes)) affords bicyclo[1.1.0]pentaphosphanes (<b>1-R</b>, R = <i>i</i>Pr, Mes), showing an unsymmetrical “butterfly” structure. The same products <b>1-R</b> are formed from K[Cp<sup>Ar</sup>] and [P<sub>5</sub>R<sub>2</sub>][GaCl<sub>4</sub>]. Cationic complexes [Cp<sup>Ar</sup>Co(η<sup>4</sup>-P<sub>5</sub>R<sub>2</sub>)][GaCl<sub>4</sub>] (<b>2-R</b>[GaCl<sub>4</sub>]) and [(Cp<sup>Ar</sup>Ni)<sub>2</sub>(η<sup>3:3</sup>-P<sub>5</sub>R<sub>2</sub>)][GaCl<sub>4</sub>] (<b>3-R</b>[GaCl<sub>4</sub>], R = <i>i</i>Pr and Cy) are obtained from [P<sub>5</sub>R<sub>2</sub>][GaCl<sub>4</sub>] and [Cp<sup>Ar</sup>M(<i>µ-</i>Br)]<sub>2</sub> (M = Co, Ni) as well as by using low valent “CpArM<sup>I</sup>’’ sources. Anion metathesis of <b>2-R</b>[GaCl<sub>4</sub>] and <b>3-R</b>[GaCl<sub>4</sub>] was achieved with Na[BArF<sub>24</sub>] (BArF<sub>24</sub> = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate). The P<sub>5</sub> framework of the resulting salts <b>2-R</b>[BArF<sub>24</sub>] can be further functionalized with nucleophiles. Thus, reaction with [Et<sub>4</sub>N]X (X = CN, Cl) gives unprecedented chloride and cyano-functionalized complexes, while organo-functionalization was achieved with CyMgCl.<br>
Functionalization of Pentaphosphorus Cations via Complexation
