Synthesis, structure, and reactivity of mixed-metal clusters bearing &#951;<SUP>1</SUP>-acetylide groups, (&#951;<SUP>5</SUP>-C<SUB>5</SUB>H<SUB>5</SUB>)MFe<SUB>2</SUB>(&#956;<SUB>3</SUB>-E)<SUB>2</SUB>(CO)<SUB>6</SUB>(&#951;<SUP>1</SUP>-CCPh) (M = Mo or W and E = Se or Te)

Reaction of Fe3(CO)9( &#956;3-E)2 (E = Se, Te) with ( &#951;5-C5H5)M(CO)3(C&#8801;CPh) (M = Mo, W), in the presence of trimethylamine-N-oxide (TMNO), in acetonitrile solvent at 60 &#176;C yields the novel mixed-metal clusters ( &#951;5-C5H5)MFe2( &#956;3-E)2(CO)6( &#951;1-CCPh) (1, E = Se, M = Mo; 2, E = Se, M = W; 3, E = Te, M = Mo; 4, E = Te, M = W) bearing &#951;1-acetylide groups. The reaction of 1 or 3 with dicobalt octacarbonyl at room temperature gives the mixed-metal clusters ( &#951;5-C5H5)MoFe2Co2( &#956;3-E)2(CO)9( &#956;-CCPh) (5, 6). Structures of 1 and 6 have been established crystallographically