Organometallic compounds of iron(O) and manganese(I)

Carbenes prefer a bridging position to a terminal coordination site. These phenomena established for molecular systems have led to the assessment that surface methylene species must be very significant in certain catalytic reactions of the Fischer-Tropsch process. The synthesis of methylene bridges on iron by the modification of bridged carbonyl ligands was investigated. New complexes of the class Fe2(CO)6X2 were isolated and studied. Reactions on the cyclopentadienyl ring takes place by exception in the Mn(η5-C5H5)(CO)3 complex while substitution reactions on the carbonyls take place only by irradiation. Due to the fact that very little structural information of π-arene complexes of manganese are available, [Mn(η6-C6Me6)(CO)3][Cr(CO)5I] was synthesised and studied by X-ray crystallography. By using Rydberg transitions, spectra of π-arene complexes of manganese(I) could be interpreted. Other techniques used in this study include 1H NMR, mass spectroscopy, ultraviolet spectroscopy, infrared spectroscopy and x-ray diffraction. 126 refs., 16 tabs., 2 figs