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 [Fe ₂ (CO) ₆ (µ-EE′)] (EE′ = SeTe, STe, SSe, S ₂ or Se ₂ ) with [Mo(CO) ₅ (thf)] (thf = tetrahydrofuran) yielded two types of mixed-metal, mixed-chalcogenide ‘hour-glass’ clusters: [Fe ₄ Mo(CO) ₁₄ (µ ₃ -E) ₂ (µ ₃ -E′) ₂ ] (E, E′ = Se, Te 1; S, Te 2; S, Se 4; S, S 7; Se, Se 9) and [Fe ₃ Mo(CO) ₁₁ (µ ₃ -E)( µ ₃ -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.