Functionalization of Pentaphosphorus Cations by Complexation

Abstract

The chemistry of polyphosphorus cations has rapidly developed in recent years,b ut their coordination behavior has remained mostly unexplored. Herein, we describe the reactivity of [P 5 R 2 ] + cations with cyclopentadienyl metal complexes.T he reaction of [Cp Ar Fe(m-Br)] 2 (Cp Ar = C 5 (C 6 H 4 -4-Et) 5 )with [P 5 R 2 ][GaCl 4 ](R= iPr and 2,4,6-Me 3 C 6 H 2 (Mes)) afforded bicyclo[1.1.0]pentaphosphanes (1-R,R = iPr and Mes), showing an unsymmetric "butterfly" structure.The same products 1-R were formed from K[Cp Ar ]a nd [P 5 R 2 ][GaCl 4 ]. The cationic complexes [Cp Ar Co(h 4 -P 5 R 2 )][GaCl 4 ]( 2-R-[GaCl 4 ], R= iPr and Cy) and [(Cp Ar Ni) 2 (h 3:3 -P 5 R 2 )][GaCl 4 ] (3-R[GaCl 4 ]) were obtained from [P 5 R 2 ][GaCl 4 ]and [Cp Ar M-(m-Br)] 2 (M = Co and Ni)a sw ell as by using low-valent "Cp Ar M I "s ources.A nion metathesis of 2-R[GaCl 4 ]a nd 3-R[GaCl 4 ]w as achieved with Na[BArF 24 ]. The P 5 framework of the resulting salts 2-R[BArF 24 ]c an be further functionalizedwith nucleophiles.Thus reactions with [Et 4 N]X (X = CN and Cl) give unprecedented cyano-and chlorofunctionalizedcomplexes,while organo-functionalizationw as achieved with CyMgCl.