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

The reaction between (η5-C5H4I)Fe(CO)2CH3 (2) and 2,5-bis[(trimethylstannyl)ethynyl]thiophene in the presence of palladium affords the iron which upon treatment with I2 is transformed to the corresponding (5). Reaction of the latter, in the presence of palladium, with the (trimethylstannyl)acetylide ML n = W(CO)3CH3, 9b, ML n = Re(CO)3) affords the polymetallaacetylide (10, ML n = W(CO)3CH3; 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.