Chalcogen–acetylide interaction and unusual reactivity of coordinated acetylide with water: synthesis and characterisation of [(η5-C5R5)Fe3(CO)6(μ3-E)(μ3-ECCH2RI)] (R=H, Me; RI=Ph, Fc; E=S, Se) and [(η5-C5R5)MoFe2(CO)6(μ3-S)(μ-SCCH2Ph)] (R=H, Me)

Photolysis of a benzene solution containing [Fe3(CO)9(μ3-E)2] (E=S, Se), [(η5-C5R5)Fe(CO)2(CCRI)] (R=H, Me; RI=Ph, Fc), H2O and Et3N results in formation of new metal clusters [(η5-C5R5)Fe3(CO)6(μ3-E)(μ3-ECCH2RI)] (R=H, RI=Ph, E=S 1 or Se 2; R=Me, RI=Ph, E=S 3 or Se 4; R=H, RI=Fc, E=S 5; R=Me, RI=Fc, E=S 6 or Se 7). Reaction of [Fe3(CO)9(μ3-S)2]with [(η5-C5R5)Mo(CO)3(CCPh)] (R=H, Me), under same conditions, produces mixed-metal clusters [(η5-C5R5)MoFe2(CO)6(μ3-S)(μ-SCCH2Ph)] (R=H 8; R=Me 9). Compounds 1–9 have been characterised by IR and 1H and 13C-NMR spectroscopy. Structures of 1, 5 and 9 have been established crystallographically. A common feature in all these products is the formation of new C-chalcogen bond to give rise to a (ECCH2RI) ligand.