The Tricarbonyliron Chalcogenolates [(OC)₃Fe(μ‐ESitBu₃)]₂ (E = S, Se, Te)

Abstract

The tricarbonyliron thiolate and selenolate [(OC)3Fe(μ‐ESitBu3)]2 (E = S, Se) were synthesized photochemically from the reaction of 2 equiv. of pentacarbonyliron with the dichalcogenides tBu3Si–E2–SitBu3 (E = S, Se). X‐ray‐quality crystals of the tricarbonyliron thiolate [(OC)3Fe(μ‐SSitBu3)]2 (monoclinic, P21/n) and selenolate [(OC)3Fe(μ‐SeSitBu3)]2 (monoclinic, P21/n) were grown from benzene. The cyclic voltammograms of [(OC)3Fe(μ‐ESitBu3)]2 (E = S, Se, Te) resemble each other. Electrochemical reduction at potential below –2.2 V or reduction of [(OC)3Fe(μ‐ESitBu3)]2 (E = S, Se, Te) with Na or K led to degradation of the complex core with the formation of the chalcogenolates [ESitBu3]– (E = S, Se, Te). The dichalcogenides tBu3Si–E2–SitBu3 (E = Se, Te) are accessible by the reaction of Na[ESitBu3] with oxygen. However, the disulfide tBu3Si–S2–SitBu3 (monoclinic, P21/c) which is used in the synthesis of tricarbonyliron thiolates [(OC)3Fe(μ‐ESitBu3)]2 as starting material, was prepared from S2Cl2 and Na[SitBu3]. Depending on the solvent used for crystallization, the sodium supersilyl chalcogenolates Na[ESitBu3] (E = S, Se) form dimeric or tetrameric structures in the solid state. Single crystals of the dimeric thiolate [Na(thf)2SSitBu3]2 (monoclinic, P21/c) were obtained from thf at –25 °C whereas crystals suitable for X‐ray diffraction of tetrameric chalcogenolates [Na(thf)ESitBu3]4 (E = S, Se) were grown from hexane at –25 °C.

Synthesis of Diiron(I) Dithiolato Carbonyl Complexes

“…Oxidative addition of the disilyl disulfide to Fe(CO) 5 under UV irradiation gives the silylthiolate Fe 2 [ μ -SSi( t -Bu) 3 ] 2 (CO) 6 . 192 The volatile Fe 2 ( μ -SCF 3 ) 2 (CO) 6 was obtained by addition of (SCF 3 ) 2 to Fe 2 (CO) 9 . 193 The related reactions of Fe(CO) 5 with XSCF 3 (X= SMe, SCF 3 ) give trace amounts of “Fe 2 ( μ -S)( μ -SCF 3 ) 2 (CO) 6 ”, which, as mentioned elsewhere, could be a perthiolate Fe 2 ( μ -SCF 3 )( μ -S 2 CF 3 ) 2 (CO) 6 .…”

The inverse sandwich complex [(K(18-crown-6))2Cp][CpFe(CO)2] – unpredictable redox reactions of [CpFe(CO)2]I with the silanides Na[SiRtBu2] (R = Me, tBu) and the isoelectronic phosphanyl borohydride K[PtBu2BH3]

“…In a preceding study 5 we have already made a comparison of cyclopentadienyliron dicarbonyl complexes with two series of isoelectronic and largely isosteric ligands, namely PPh 2 Me, 6 [PPh 2 BH 3 ] − , 6 and [SiPh 2 Me] −7 and SPtBu 3 , 8 [SPtBu 2 BH 3 ] −8 and [SSitBu 3 ] − . 9 In this report we have concluded that, with respect to electron donor strength, phosphanyl borohydrides occupy an intermediate position between phosphanes (weakest donors) and silyl ligands (strongest donors). 5 The same is true for the thio derivatives, although the differences are smaller.…”

Redetermination of (acetonitrile-κN)dicarbonyl(η5-cyclopentadienyl)iron(II) tetrafluoridoborate

“…For background to this work, see: Kü ckmann et al (2005Kü ckmann et al ( , 2007Kü ckmann et al ( , 2008Kü ckmann et al ( , 2010; Lerner (2005); Sä nger et al (2012). For a previous (incomplete) structure determination of the title compound, see: Fadel et al (1979).…”