| Popis: |
The matrix IR absorbance spectra of fulvenone, a reactive intermediate in the pyrolysis of lignin, and three of its thermal dissociation products were recorded and analysed using a flash pyrolysis microreactor and ab initio calculations. The predicted spectra of fulvenone, penta-1,2-diene-4-yne, penta-1,3-diyne, and n-C5H3��� matched well with the experimentally observed transitions, and are in good agreement with existing literature data. The cyclic C5H4 isomer, cyclopentadienylidene, could not be conclusively identified, suggesting that fulvenone is the last relatively stable cyclic species in this pyrolytic chain of reactions. The evolution of the IR data with increasing extent of the pyrolysis shows a gradual trend of dissociation of complex organic molecules towards highly unsaturated hydrocarbons. The isomer-specific analysis by IR assignments of these pyrolytic pathways helps pave the way for further study of biomass thermal reactions, towards possible uses of biomass as a renewable source of energy. |
