An Approach to Mixed P(n)A(sm) Ligand Complexes

The reaction of a P4 butterfly complex with yellow arsenic yields the largest mixed Pn Asm 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) -Pn As4-n )] and [Cp'''Fe(η(5) -Pn As5-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) -Pn As4-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.