An Approach to Mixed PnAsm Ligand Complexes

The reaction of a P₄ butterfly complex with yellow arsenic yields the largest mixed P_nAs_m ligand complexes synthesized to date. {Cp′′′Fe(CO)₂}₂(μ,η^1:1‐P₄)] reacts with As₄ to yield {Cp′′′Fe}₂(μ,η^4:4‐P_nAs_4‐n)] and Cp′′′Fe(η⁵‐P_nAs_5‐n)]. Mass spectrometry together with NMR spectroscopy and X‐ray crystallography give clear evidence about the arrangement of the E positions within the cyclo‐E₅ and E₄ moieties of the products. Moreover, the results of DFT calculations agree well with the experimental determined outcomes. By coordinating the E₄ complex {Cp′′′Fe}₂(μ,η^4:4‐P_nAs_4‐n)] with CuCl, a rearrangement of the E positions occurs in favor with a preferred phosphorus coordination towards copper atoms in the resulting 1D polymeric chain.