Dc. Kitchen et al., DETERMINATION OF ABSOLUTE PRODUCT BRANCHING RATIOS IN MASS-SPECTROMETRIC EXPERIMENTS - DETECTING ACETYL RADICALS AT CH2CO+, Journal of physical chemistry, 100(13), 1996, pp. 5200-5204
The paper describes a general method for determining absolute branchin
g ratios in mass spectrometric experiments. The method overcomes the c
hronic obstacle that the daughter ion fragmentation pattern of radical
products is usually unknown. We report the absolute product branching
ratio for competing primary C-Cl and C-C bond fission in chloroaceton
e after excitation on the (1)n pi absorption band. To determine this
branching ratio, acetyl chloride is used to calibrate the relative det
ection efficiency of acetyl radicals at the CH2CO+ daughter ion relati
ve to Cl atoms at Cl-35(+). We also calculate the daughter ion product
ion probability for CH2CO+ formed from internally excited CH3CO radica
ls.