ISSN:
0887-624X
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Polymerization of homologues of 1-(trimethylsilyl)-1-propyne [CH3C≡CSi(CH3)3] was studied. CH3C≡CSi(CH3)2(n-C6H13) (I) polymerized with 1 : 1 mixtures of TaCl5 and organometallic cocatalysts (e.g., Ph4Sn and Ph3Bi) to produce in good yields a polymer having a weight-average molecular weight (Mw) over 1 × 106. CH3C≡CSi(CH3)2 Ph (II) and CH3C≡CSi(C2H5)3 (III) formed polymers having Mw's of ∼ 5 × 105 in moderate yields in the presence of TaCl5-based catalysts. In contrast, none of CH3C≡CSi(CH3)2(i-C3H7), CH3C—CSi(CH3)2(t,-C4H9), C2H5C≡CSi(CH3)3, and n,-C4H9C≡CSi(CH3)3 polymerized, which is attributed to the steric effect of the monomers. Some other 1-silyl-1-propynes also failed to polymerize. The three new polymers formed from (I)-(III) had the structure \documentclass{article}\pagestyle{empty}\begin{document}$\rlap{--} [{\rm CCH}_{\rm 3} \hbox{=\hskip-2pt=} {\rm C(SiRR'R''}\rlap{--} ]_n$\end{document} according to IR and 13C-NMR spectra. They were white solids, soluble in low-polarity solvents (e.g., toluene and chloroform) and stable enough in air at room temperature.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1987.080250513
