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THOMAS K. ORMOND, ADAM M. SCHEER, G. BARNEY ELLISON, Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215; MARK R. NIMLOS, Center for Renewable Chemical, Technologies & Materials, NREL, 1617 Cole Blvd., Golden, CO 80401; JOHN W. DAILY, Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309-0427; JOHN F. STANTON, Institute for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, TX 78712.
We are developing a resistively-heated SiC µtubular reactor with a 100 µsec residence time to study the thermal cracking of biomass monomers. The decomposition products are identified by two independent techniques: 118.2 nm VUV photoionization mass spectrometry (PIMS) and matrix infrared spectroscopy. Many lignins thermally crack to produce cyclopentadienone (m/z 80) and its derivatives. Subsequent decomposition of these cyclopentadienones results in formation of substituted acetylenes which are known precursors to polycyclic aromatic hydrocarbons and soot.
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\endwrapfigure Due to its anitaromatic character, cyclopentadienone is highly reactive and presents an interesting spectroscopic system. Pyrolysis of o -phenylene sulfite (m/z 156) is a convenient precursor for cyclopentadienone. In this work we report the polarized matrix infrared absorption spectra of cyclopentadienone and d4-cyclopentadienone. The PIMS results corroborate the thermal decomposition steps of phenylene sulfite. Ab initio coupled-cluster anharmonic force field calculations are used to guide the vibrational assignments.