Synthesis and characterisation of [Fe2M3(μ4-E)(μ3-E′)(CO)17] and [Os3(μ3-E)(μ3-E′)(CO)9] (M=Os or Ru; E=S, Se, Te; E′=Se, Te)

A set of new chalcogen-bridged mixed metal clusters [Fe2Os3(μ4-E)(μ3-E′)(CO)17] (2, EE′=SeTe; 3, EE′=STe; 4, EE′=Se2; 5, EE′=SSe) and [Fe2Ru3(μ4-E)(μ3-E′)(CO)17] (12, EE′=SeTe; 13, EE′=STe; 14, EE′=Se2; 15, EE′=SSe) has been synthesised by facile methods. Thermolysis or photolysis of compounds 2, 3 and 5 afforded the new triosmium mixed chalcogenide clusters [Os3(μ3-E)(μ3-E′)(CO)9] (7, EE′=SeTe; 8, EE′=STe; 10, EE′=SSe). All new compounds were characterised by IR and 1H-, 77Se- and 125Te-NMR spectroscopy. Clusters 8, 9 and 12 were structurally characterised by single crystal X-ray diffraction methods.