E(4) Transfer (E=P, As) to Ni Complexes

The use of [Cp′′(2)Zr(η(1:1)‐E(4))] (E=P (1 a), As (1 b), Cp′′=1,3‐di‐tert‐butyl‐cyclopentadienyl) as phosphorus or arsenic source, respectively, gives access to novel stable polypnictogen transition metal complexes at ambient temperatures. The reaction of 1 a/1 b with [Cp(R)NiBr](2) (Cp(R)=Cp(Bn) (1,2,3,4,5‐pentabenzyl‐cyclopentadienyl), Cp′′′ (1,2,4‐tri‐tert‐butyl‐cyclopentadienyl)) was studied, to yield novel complexes depending on steric effects and stoichiometric ratios. Besides the transfer of the complete E(n) unit, a degradation as well as aggregation can be observed. Thus, the prismane derivatives [(Cp′′′Ni)(2)(μ,η(3:3)‐E(4))] (2 a (E=P); 2 b (E=As)) or the arsenic containing cubane [(Cp′′′Ni)(3)(μ(3)‐As)(As(4))] (5) are formed. Furthermore, the bromine bridged cubanes of the type [(Cp(R)Ni)(3){Ni(μ‐Br)}(μ(3)‐E)(4)](2) (Cp(R)=Cp′′′: 6 a (E=P), 6 b (E=As), Cp(R)=Cp(Bn): 8 a (E=P), 8 b (E=As)) can be isolated. Here, a stepwise transfer of E(n) units is possible, with a cyclo‐E(4) (2−) ligand being introduced and unprecedented triple‐decker compounds of the type [{(Cp(R)Ni)(3)Ni(μ(3)‐E)(4)}(2)(μ,η(4:4)‐E′(4))] (Cp(R)=Cp(Bn), Cp′′′; E/E′=P, As) are obtained.