The Tricarbonyliron Chalcogenolates [(OC)₃Fe(μ‐ESi<i>t</i>Bu₃)]₂ (E = S, Se, Te)

Abstract

Abstract The tricarbonyliron thiolate and selenolate [(OC) 3 Fe(μ‐ESi t Bu 3 )] 2 (E = S, Se) were synthesized photochemically from the reaction of 2 equiv. of pentacarbonyliron with the dichalcogenides t Bu 3 Si–E 2 –Si t Bu 3 (E = S, Se). X‐ray‐quality crystals of the tricarbonyliron thiolate [(OC) 3 Fe(μ‐SSi t Bu 3 )] 2 (monoclinic, P 2 1 / n ) and selenolate [(OC) 3 Fe(μ‐SeSi t Bu 3 )] 2 (monoclinic, P 2 1 / n ) were grown from benzene. The cyclic voltammograms of [(OC) 3 Fe(μ‐ESi t Bu 3 )] 2 (E = S, Se, Te) resemble each other. Electrochemical reduction at potential below –2.2 V or reduction of [(OC) 3 Fe(μ‐ESi t Bu 3 )] 2 (E = S, Se, Te) with Na or K led to degradation of the complex core with the formation of the chalcogenolates [ESi t Bu 3 ] – (E = S, Se, Te). The dichalcogenides t Bu 3 Si–E 2 –Si t Bu 3 (E = Se, Te) are accessible by the reaction of Na[ESi t Bu 3 ] with oxygen. However, the disulfide t Bu 3 Si–S 2 –Si t Bu 3 (monoclinic, P 2 1 / c ) which is used in the synthesis of tricarbonyliron thiolates [(OC) 3 Fe(μ‐ESi t Bu 3 )] 2 as starting material, was prepared from S 2 Cl 2 and Na[Si t Bu 3 ]. Depending on the solvent used for crystallization, the sodium supersilyl chalcogenolates Na[ESi t Bu 3 ] (E = S, Se) form dimeric or tetrameric structures in the solid state. Single crystals of the dimeric thiolate [Na(thf) 2 SSi t Bu 3 ] 2 (monoclinic, P 2 1 / c ) were obtained from thf at –25 °C whereas crystals suitable for X‐ray diffraction of tetrameric chalcogenolates [Na(thf)ESi t Bu 3 ] 4 (E = S, Se) were grown from hexane at –25 °C.