Controlling bond rearrangement in ethanol: An interesting failure?

In the past, we have successfully used adaptive control coupled to ultrafast pulse shaping to influence bond rearrangement induced by photofragmentation of a number of small molecules such as acetylene, ethylene, ethane, and methanol. Our standard control objective is the improvement of a ratio of ionization products, such as D₂H⁺/D₃⁺ from CD₃OH. Typically, the shaped laser pulse optimized by the search algorithm can enhance the desired ratio of product channels by a factor of two or three. When this technique was extended to ethanol, however, we could not substantially improve either the D₂H⁺/D₃⁺ or D₃⁺/D₂H⁺ ratio from CH₃CD₂OD. This talk discusses that puzzle.