Synthesis, spectroscopic and structural characterisation of (CO)6Fe2′{μ-C(H)(CH3)}2 and (CO) 6Fe2{-EC(H)((CH3)E′} (E, E′  S, Se, Te)

Room temperature reaction of (CO) 6 Fe 2 (μ-EE′) (E≠ E′; E, e′  S, Se, Te; E  E′  S, Se, Te) with diazoethane yielded two types of compound: (CO) 6 Fe 2 EE′{μ-C(H)CH 3 } 2 (1, 27%, E  E′  S; 2, 24%, E  S, E′  Se; 3, 21%, E  E′  Se; 5, 19%, E S, E′  Te; 7, 12%, E  Se, E ′  Te) and (CO) 6 Fe 2 {μ-EC(H)CH 3 )E′} (4, 13%, E  E′  Se; 16%, E  S, E′  Te; 8, 22%, E  Se, E′  Te; 9, 28%, E  E′  Te). Compounds 1–9 were characterized by IR 1 H, 13 C, 77 Se and 125 Te NMR spectroscopy. Structures of 1, 3, 5, 8 and 9 were established by crystallographic methods. Compounds 1, 3 and 5 are isomorphic and isostructural and their structure consists of a distorted rhombus in which Fe and E (E  S, Se, Te) occupy adjacent comers. Two C(H)(CH 3 ) moieties bridge opposite FeE bonds and give roughly a chair conformation. Compounds 8 and 9 are isomorphic and isostructural and their structure consists of an Fe 2 TeE (E  Se, Te) tetrahedrally core containing a C(H)(CH 3 ) group as bridge between two wing-tips of chalcogen atoms.