An ab initio G3-type study of the indene formation pathways

PHYS 425

Vadim V. Kislov, kvv_bne@mail.ru and Alexander M Mebel, mebela@fiu.edu. Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33193
Extensive ab initio G3 type calculations of potential energy surfaces, combined with statistical theory calculations of reaction rate constants have been applied to study various possible pathways relevant to indene formation in combustion flames. Those pathways involve benzene (phenyl), toluene (benzyl), cyclopentadiene (cyclopentadienyl), fulvene (fulvenyl) and naphthalene (naphthyl) as the initial reactants, which then can react with abundant small hydrocarbon molecules or their radicals (CH3, C3H3, C2H2, C4H4) producing indene after a certain number of rearrangements and a ring closure. The reaction pathway starting from the reaction of naphthyl radical with molecular oxygen was found to be high energetically favorable and can be considered as one of the major indene formation mechanisms. The other two most probable routes involving acetylene addition to benzyl radical and cyclopentadienyl represent the hydrogen abstraction acetylene addition mechanism of indene synthesis. Both routes demonstrate low barriers and high reaction rates. The pathways involving C3H3 (propargyl) and C4H4 (vinylacetylene) additions proceed via formation of biradical intermediates with relatively high barriers, and, therefore, can be considered only as minor reaction channels.
 

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006