Flash vacuum pyrolysis and photolysis of 3,3,5,5-tetramethylpyrazolin-4-one - A matrix isolation study

The flash vacuum pyrolysis of 3,3,5,5-tetramethylpyrazolin-oxide 9 as the m ajor products. The reaction of 4-one (4) with subsequent trapping of the pr oducts in argon tetramethylallene 13 with oxygen atoms yields the same at 1 0 K results in the formation of a complex product mixture product mixture o f 5 and 9 and thus provides an independent with tetramethylcyclopropanone ( 5) as one of the minor route to these species. The experimental IR spectra of 5 and constituents. The 193 nm photochemistry of matrix-isolated 9 are i n good agreement with the results from DFT 4 is much cleaner, yielding cycl opropanone 5 and allene calculations.