Mixed Fe/Mo mixed-chalcogenide 'hour-glass' clusters,[Fe₄Mo(CO)₁₄(μ₃-E)₂(μ₃-E')₂] and [Fe₃Mo(CO)₁₁(μ₃-E)(μ₃-E')(μ-E'-E')](E, E' = S, Se or Te)

Abstract

The room-temperature reactions of [Fe₂(CO)₆(μ-EE')] (EE' = SeTe, STe, SSe, S2 or Se2) with [Mo(CO)₅(thf)] (thf = tetrahydrofuran) yielded two types of mixed-metal, mixed-chalcogenide 'hour-glass' clusters: [Fe₄Mo(CO)1₄(μ₃-E)₂ (μ₃-E')₂] (E, E' = Se, Te 1; S, Te 2; S, Se 4; S, S 7; Se, Se 9) and [Fe₃Mo(CO)₁₁(μ₃-E)(μ₃-E')(μ-E'-E ')] (E, E' = S, Te, E'-E' = Te-Te 3; E, E' = S, Se, E'-E' = Se-Se 5; E, E' = S, S, E'-E' = S-Se 6; E, E' = S, S, E'-E' = S-S 8; E, E' = Se, Se, E'-E' = Se-Se 10). The crystal structures of 2, 5, 6 and 8 were elucidated by X-ray methods. The structure of 2 consists of two distorted square-pyramidal cores in each of which the alternate corners of the base are occupied by Fe and chalcogen atoms and a Mo atom occupies the common apical site. In 5, 6 and 8 a Mo atom occupies the common apical site of a square-pyramidal core and a tetrahedral core. The base of the square-pyramidal unit consists of alternate Fe and chalcogen atoms and the tetrahedral base consists of a Fe atom and two chalcogen atoms.