Cross-conjugated polymers via condensation of a zirconocene alkynyl(benzyne) derivative generated by thermolysis of Cp2ZrMe(C6H4C≡CSiMe3)

Article abstract of DOI:10.1016/0022-328X(96)06353-X

The complex Cp₂ZrMe(C₆H₄C≡CSiMe₃) (4) has been synthesized by reaction of Cp₂ZrMeCl and LiC₆H₄C≡CSiMe₃ (generated in situ from reaction of ⁿBuLi with BrC₆H₄C≡CSiMe₃ at -95°C). Thermolysis of 4 in THF afforded an unsaturated, organometallic polymer [Cp₂Zr(C₆H₃C=CSiMe₃)]_n (7) in ca. 80% yield (M_w/M_n=4000/2000). Polymer 7 was investigated as a synthon for other unsaturated polymers. It reacts with hydrochloric acid to form a new phenylene-1,1-vinylene polymer [-C(=CHSiMe₃)-1,4-C₆H₄-]_n (8), and with sulfur dichloride to give poly(1-trimethylsilyl-2-benzo[b]thiophene) (9). Thermolysis of two similar compounds, Cp₂ZrMe(C₆H₄C≡CCH3) (5) and Cp₂ZrMe(C₆H₄C₆H₄C≡CSiMe₃) (6), did not give polymers.