Iodination of cyclo‐E(5)‐Complexes (E=P, As)

In a high‐yield one‐pot synthesis, the reactions of [Cp*M(η(5)‐P(5))] (M=Fe (1), Ru (2)) with I(2) resulted in the selective formation of [Cp*MP(6)I(6)](+) salts (3, 4). The products comprise unprecedented all‐cis tripodal triphosphino‐cyclotriphosphine ligands. The iodination of [Cp*Fe(η(5)‐As(5))] (6) gave, in addition to [Fe(CH(3)CN)(6)](2+) salts of the rare [As(6)I(8)](2−) (in 7) and [As(4)I(14)](2−) (in 8) anions, the first di‐cationic Fe‐As triple decker complex [(Cp*Fe)(2)(μ,η(5:5)‐As(5))][As(6)I(8)] (9). In contrast, the iodination of [Cp*Ru(η(5)‐As(5))] (10) did not result in the full cleavage of the M−As bonds. Instead, a number of dinuclear complexes were obtained: [(Cp*Ru)(2)(μ,η(5:5)‐As(5))][As(6)I(8)](0.5) (11) represents the first Ru‐As(5) triple decker complex, thus completing the series of monocationic complexes [(Cp(R)M)(2)(μ,η(5:5)‐E(5))](+) (M=Fe, Ru; E=P, As). [(Cp*Ru)(2)As(8)I(6)] (12) crystallizes as a racemic mixture of both enantiomers, while [(Cp*Ru)(2)As(4)I(4)] (13) crystallizes as a symmetric and an asymmetric isomer and features a unique tetramer of {AsI} arsinidene units as a middle deck.