Combined Use of Palladium-Catalyzed Carbon−Carbon and Metal−Carbon Bond Formations for the Construction of Poly(metallaacetylide) Tethers

The reaction between (η 5 -C 5 H 4 I)Fe(CO) 2 CH 3 ( 2 ) and 2,5-bis[(trimethylstannyl)ethynyl]thiophene in the presence of palladium affords the iron which upon treatment with I 2 is transformed to the corresponding ( 5 ). Reaction of the latter, in the presence of palladium, with the (trimethylstannyl)acetylide ML n = W(CO) 3 CH 3, 9b, ML n = Re(CO) 3 ) affords the polymetallaacetylide ( 10, ML n = W(CO) 3 CH 3; 11, ML n = Re(CO) 3 ). Trimethyltin derivatives of poly(ethynylthiophene) oligomers have been also prepared and tested for their use as spacers in poly(metallaacetylide) complexes.