Simultaneous Orthogonal Methods for the Real-Time Analysis of Catalytic Reactions

Continuous monitoring of catalyzed reactions using infrared spectroscopy (IR) measures the transformation of reactant into product, whereas mass spectrometry delineates the dynamics of the catalytically relevant species present at much lower concentrations, a holistic approach that provides mechanistic insight into the reaction components whose abundance spans 5 orders of magnitude. Probing reactions to this depth reveals entities that include precatalysts, resting states, intermediates, and also catalyst impurities and decomposition products. Simple temporal profiles that arise from this analysis aid discrimination between the different types of species, and a hydroacylation reaction catalyzed by a cationic rhodium complex is studied in detail to provide a test case for the utility of this methodology.