FTIR SPECTROSCOPIC INVESTIGATION OF MATRIX-ISOLATED ISOMERIZATION ANDDECOMPOSITION PRODUCTS OF IONIZED ACETONE - GENERATION AND CHARACTERIZATION OF 1-PROPEN-2-OL

An electron bombardment - matrix isolation apparatus was used to gener ate and isolate products from acetone isomerization and decomposition for infrared spectroscopic examination. Bombardment of a dilute aceton e/argon gas mixture (1:400) above a 12 K matrix isolation substrate le ads to the direct observation of neutral fragmentation and isomerizati on products. A major product is 1-propen-2-ol, the enolic tautomer of acetone, whose IR absorption spectrum, and that of its perdeutero anal og, are interpreted with the aid of ab initio computations. The observ ation of matrix-isolated decomposition products of acetone such as ace tyl radicals, ketene, methane, and CH3 . is interpreted in terms of io n and neutral decomposition processes occurring in the gas phase above the matrix surface and during matrix condensation. The detection of m atrix-isolated 1-propen-2-ol is consistent with a process involving ac etone ionization, isomerization, neutralization, and stabilization, an approach that may have general utility in the generation of other the rmodynamically unfavourable neutral isomers of organic molecules.