Kinetic and mechanistic investigations in homogeneous catalysis using operando UV/vis spectroscopy

This study presents three examples in which the methodological approach of operando UV/vis spectroscopy is demonstrated using both submersible optrodes and the stopped flow/diode array technique. First, the submersible optrode is applied for the monitoring of stoichiometric reactions, that is the hydrogenation of cyclooctadiene (cod) in the rhodium diphosphine complex [Rh(Me-Du-PHOS)(cod)]BF4 (Me-DuPHOS = 1,2-bis(-2,5-dimethyl-phospholano)benzene), which is a typical catalyst precursor in asymmetric hydrogenation. Second, the determination of stability constants for rhodium diphosphine arene complexes is shown. The third example presents UV/vis spectroscopy of zirconium and hafnium complexes with ethylene as a gaseous reaction partner using the stopped flow/diode array technique.