The reaction of Pt(PEt3)3 with the silicon-bridged ferrocenophane Fe(η5-C5H4)2SiMe2 1 at 60°C resulted in the insertion of a platinum(0) Pt(PEt3)2 fragment into the strained Si-C bond to yield the first platinasilaferrocenophane Fe(η5-C5H4)2Pt(PEt 3)2SiMe2 4. Complex 4 serves as a model for the proposed intermediate during the transition metal-catalyzed ring-opening polymerization (ROP) of 1. The reactivity of 4 was illustrated by the insertion of diphenylacetylene into the Pt-Si bond at elevated temperatures to yield a ferrocenophane Fe(η5-C3H4)2Pt(PEt 3)2C(Ph)C(Ph)SiMe2 5 with a cis Pt-C=C-Si bridge. Both 4 and 5 were fully characterized spectroscopically and by single crystal X-ray diffraction. Despite the reactivity of the Pt-Si bond, the platinasilaferrocenophane 4 was inactive as a ROP catalyst for 1 even at 95°C. However, addition of BH3·THF co-catalyst rendered 4 active towards the ROP of 1 at 25°C, presumably via abstraction of one or more PEt3 ligands, affording low molecular weight [Mn (number average molecular weight) = ca. 1720-4695; PDI (polydispersity index) = 1.51-1.73], cyclic poly(ferrocenylsilanes) 6.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of the Chemical Society - Dalton Transactions|
|State||Published - 1998|
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