Synthesis, spectroscopic and structural characterisation of (CO)(6)Fe(2)EE'{mu-C(H)(CH3)}(2) and (CO)(6)Fe-2{mu-EC(H)(CH3)E'} (E,E'=S, Se, Te)

Abstract

Room temperature reaction of (CO)(6)Fe-2(mu-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'{mu-C(H)CH3}(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{mu-EC(H)(CH3)E'} (4, 13%, E = E' = Se; 6, 16%, E = S, E' = Te; 8, 22%, E = Se, E' = Te; 9, 28%, E = E' = Te). Compounds 1-9 were characterised by IR and H-1, C-13, Se-77 and Te-125 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 corners. Two C(H)(CH3) 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) tetrahedral butterfly core containing a C(H)(CH3) group as bridge between two wing-tips of chalcogen atoms.