A difficulty of studies on chemical kinetics are the reaction time scales and detection of their intermediates. Rapid Freeze-Quench (RFQ) is one of the most common techniques to investigate... Show moreA difficulty of studies on chemical kinetics are the reaction time scales and detection of their intermediates. Rapid Freeze-Quench (RFQ) is one of the most common techniques to investigate chemical kinetics. Since the intermediates of many reactions are paramagnetic, coupling RFQ to Electron Paramagnetic Resonance (EPR) is a desirable goal, especially at high-frequency (HF-EPR). HF-EPR offers high resolution and better spectral definition. However, collection of RFQ samples for HF-EPR is troublesome. In Chapter 2, the successful coupling of RFQ to HF-EPR at 275 GHz is described. Chapter 3 describes the development of Temperature-Cycle EPR (T-Cycle EPR), a novel high-frequency EPR technique that couples laser-induced T-jumps of the sample to a high-frequency 275 GHz EPR spectrometer, to detect short-lived paramagnetic intermediates and kinetics of chemical reactions in aqueous solutions. Chapter 4 discusses the application of T-Cycle EPR on a model reaction unfolding over hundreds of milliseconds, proving the technique is suitable to study many (bio)chemical systems. Chapter 5 shows an attempt to apply T-Cycle EPR to an enzymatic system on the sub-second time. T-Cycle EPR experiments at 275 GHz are performed on the reoxidation of a mutant of Small Laccase in the sub-second time regime, without making use of RFQ. Show less
