Iodination ofcyclo-E5-Complexes (E=P, As)

In a high-yield one-pot synthesis, the reactions of [Cp*M(eta(5)-P-5)] (M=Fe (1), Ru (2)) with I(2)resulted in the selective formation of [Cp*MP6I6](+)salts (3,4). The products comprise unprecedented all-cistripodal triphosphino-cyclotriphosphine ligands. The iodination of [Cp*Fe(eta(5)-As-5)] (6) gave, in addition to [Fe(CH3CN)(6)](2+)salts of the rare [As6I8](2-)(in7) and [As4I14](2-)(in8) anions, the first di-cationic Fe-As triple decker complex [(Cp*Fe)(2)(mu,eta(5:5)-As-5)][As6I8] (9). In contrast, the iodination of [Cp*Ru(eta(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)(mu,eta(5:5)-As-5)][As6I8](0.5)(11) represents the first Ru-As(5)triple decker complex, thus completing the series of monocationic complexes [(Cp(R)M)(2)(mu,eta(5:5)-E-5)](+)(M=Fe, Ru; E=P, As). [(Cp*Ru)(2)As8I6] (12) crystallizes as a racemic mixture of both enantiomers, while [(Cp*Ru)(2)As4I4] (13) crystallizes as a symmetric and an asymmetric isomer and features a unique tetramer of {AsI} arsinidene units as a middle deck.