HYDROGEN ATOM ABSTRACTION BY ETHYL-d5 RADICALS. PART I

Abstract

The photolysis of 3-pentanone-d10 has been used as a source of deuterated ethyl radicals and some of their hydrogen abstraction reactions studied over the temperature range 50–300 °C.The compounds neopentane, n-butane, and isobutane were chosen as representative of the basic structural features in the alkane series. The activation energies for abstraction [Formula: see text] are respectively 12.60 ± 0.7, 10.4 ± 0.75, and 8.9 ± 0.6 kcal/mole and the pre-exponential factors (log10(A8/A4)) are 0.300 ± 0.09, 0.082 ± 0.09, and −0.334 ± 0.066 where[Formula: see text]For abstraction of a deuterium atom from the ketone the values obtained are [Formula: see text] in agreement with previous investigations (1, 2).The value of the disproportionation to combination ratio for C2D5 radicals is 0.0985 ± 0.008 independent of temperature.