Dithiocarbamate derivatives of μ-thiocarbyne complexes: Synthesis and X-ray molecular structure of [Fe2(μ-CS)(μ-CSMe) (μ-S2CNMe2)Cp2]

Article abstract of DOI:10.1016/S0022-328X(02)01652-2

Reaction of [Fe₂(μ-CS)(μ-CSMe)Cp₂(CO)₂]⁺ (1) with sodium N,N-dimethyldithiocarbamate [Me₂dtc]Na affords a mixture of the dithiocarbene [FeFe(μ-CS){μ-C(SMe)SC(S)NMe₂}Cp(CO)] (2) and the thiocarbyne [Fe₂(μ-CS)(μ-CSMe)(μ-S₂CNMe₂)Cp₂] (3). Complex 2 is quantitatively converted into 3 by photochemical irradiation. The X-ray molecular structure of 3 demonstrates the presence of three bridging ligands and exhibits the shortest Fe-Fe interaction found in similar systems [2.453(1) A?]. Complex 3 can also be obtained by reacting [Me₂dtc]^- with the di-solvento thiocarbyne [Fe₂(μ-CS)(μ-CSMe)(NCMe)₂Cp₂]⁺ (1a). By contrast no stable addition product has been isolated in analogous reactions involving the thiocarbyne [Fe₂(μ-CO)(μ-CSMe)Cp₂(CO)₂]⁺ (1b). The [Me₂dtc]^- nucleophilic addition at the μ-C to form [Fe₂(μ-CO){μ-C(CN)SC(S)NMe₂}Cp₂(CO)₂] (4a) is obtained starting from [Fe₂(μ-CO){μ-C(CN)(SMe₂)}Cp₂(CO)₂]SO₃CF₃ (1d). Photochemical reaction of the cyanocarbene 4a causes intramolecular ring closure affording [FeFe(μ-CO){μ-C(CN)SC(S)NMe₂}Cp₂(CO)] (5a).