Development of ambient mass spectrometry methods for investigating iron-catalyzed oxidation reactions

Improvement of catalytic reactions relies on detailed understanding of the reaction mechanism, and this in turn depends on the ability to detect, characterize, and identify reaction intermediates that often have extremely short lifetimes or are highly unstable when removed from the reaction medium. For this reason, numerous techniques and approaches have been developed over the years with the goal of identifying catalytic reaction intermediates. While spectroscopic methods often give indirect insight into a reaction mechanism, mass spectrometry (MS) is unparalleled in the level of chemical specificity. Ambient MS methods can capture fleeting intermediates of catalytic cycles with reaction times of a few milliseconds or less, and the novel methodology described in this paper can simultaneously reduce the reaction time and increase the chemical complexity of these reactions compared to previous ambient MS methods. This novel method is characterized both for its scope of chemical reactions as well as its analytical capabilities. The new methodology is then applied to study a number of interesting catalytic systems. Finally, it is proposed, based on the successes of the new method towards the characterization of said catalytic reactions, that increasingly complex catalytic transformations be explored