Fullerene dications and trications as initiators in the gas-phase `ball-and-chain` polymerization of allene and propyne: Observation of a remarkable periodicity in chain growth with allene
- York Univ., North York (Canada)
- Univ. of British Columbia, Vancouver (Canada)
- Univ. of New South Wales, Canberra (Australia)
The chemistry initiated by C{sub 60}{sup x+} (with x = 1, 2, and 3) in allene and propyne has been tracked in the gas phase. Reaction rate coefficients and product distributions were measured with the Selected-Ion Flow Tube (SIFT) technique operating at 294 {+-} 3 K and at a helium buffer-gas pressure of 0.35 {+-} 0.01 Torr. C{sub 60}{sup .+} does not react with allene and propyne under SIFT conditions, but multiple addition was observed with C{sub 60}{sup 2+}. Multiple addition was also observed in the reaction of propyne with C{sub 60}{sup 3+}, but allene reacted only by electron transfer with this cation. Up to 16 molecules of allene were observed to add to C{sub 60}{sup 2+} with a remarkable periodicity in reactivity: even-numbered adducts react approximately 10 times faster than odd-numbered adducts. Multi-collision induced dissociation (CID) experiments demonstrated that the observed multiple-adduct ions have a `ball-and-chain` structure. Mechanisms are proposed for the sequential addition reactions and for the formation of C{sub 6}H{sub 7}{sup +} and C{sub 9}H{sub 12}{sup +} which was seen to compete with multiple addition in the reactions of allene with C{sub 60}{sup 2+} and of propyne with C{sub 60}{sup 3+}. The multiple-addition reactions are proposed to occur by chain propagation. 38 refs., 8 figs., 1 tab.
- OSTI ID:
- 466336
- Journal Information:
- Journal of the American Chemical Society, Vol. 119, Issue 8; Other Information: PBD: 26 Feb 1997
- Country of Publication:
- United States
- Language:
- English
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