General Considerations. All manipulations involving organoruthenium
complexes were performed under argon using standard highvacuum
or Schlenk tube techniques, or in an MBraun glovebox
containing less than 1 ppm oxygen and water. Solvents were dried and
distilled under argon before use employing standard drying agents.25
Only materials of high purity as indicated by NMR spectroscopy were
used in the calorimetric experiments. NMR spectra were recorded using
Varian Gemini 300-MHz or Varian Unity 500-MHz spectrometers.
Calorimetric measurements were performed using a Calvet calorimeter
(Setaram C-80) which was periodically calibrated using the TRIS
reaction26 or the enthalpy of solution of KCl in water.27