Iodination of cyclo-E -Complexes (E=P, As).

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