Characterization of the pyrolysis products of 2-pyrone via matrix-isolation FTIR

Abstract

One commonly observed product of the pyrolysis of many types of biomass is the cyclic oxygenated heterocycle 2-pyrone (2H-Pyran-2-one). Applying matrix-isolation techniques, the thermal decomposition products of 2-pyrone were identified by depositing a diluted mixture of sample and argon through a heated SiC tube onto a cold CsI window, which was then characterized by FT-IR. Experimental spectra collected following pyrolysis at 1400 K indicate the formation of acetylene, vinylacetylene, propargyl, propyne, allyl, carbon dioxide, carbon monoxide, ketene, and furan. Several bands in the vicinity of the antisymmetric CCO stretch of ketene are tentatively assigned to vinylketene and formylvinylketene. Computational analysis using Gaussian 09 at the B3LYP/6-311++G (d,p) level of theory was performed to further confirm product assignments. The results of this study are consistent with published theoretical and computational studies of the pyrolysis of furfural, of which 2-pyrone is a reaction intermediate.