Approximately 1.0 mg of Cp ⋆ RuCl(cod) as a solid brownish powder were weighed onto weighing paper. No special precautions against exposure to ambient oxygen or water were taken. The catalyst was added to the HPLC vial, which was then promptly capped and vortexed for approx. 15 seconds, until the catalyst was completely dissolved. The vial was added to the autosampler of an Agilent 6545 quadrupole time-of-flight LC-MS incubated at 20 °C. The LC-MS system was programmed to inject 0.2 µL from the vial at regular intervals after addition of the catalyst.