Electrochemistry of (Dihapto-Buckminster-FoIIererie) Pentacarbonyi Tungsten(G)

摘要

The sunlight-induced photosynthesis and characteriza-tion of (diliapto-[60]fullerene) pentacarbonyi tungsten(O), (r|2-CfiQ)W(CO)5, and the kinetics of its ligand-exchange reactions are published experiments for the inorganic chemistry laboratory (1, 2). The former experiment (1) promotes laboratory skills, student understanding of inorganic chemistry concepts such as JC backbonding and TC donation, symmetry, and prediction of infrared spectra in the CO stretching region (Vco)- The educational objectives of the latter experiment (2) are (i) to promote student understanding of the relation between kinetics, mechanisms, and the role of solvents in ligand-exchange reactions, (ii) to use activation parameters to confirm or disprove a mechanism, and (iii) to understand the relation between the enthalpy of activation of the W-CGO bond breakage and the thermodynamic W-Cgo bond enthalpy. Combining both laboratory experiments, the students are provided with hands-on exercises where they integrate chemical knowledge and use IR, 13C NMR, and 'H NMR data to understand and explain the chemical structure of (η~2C60)W(CO)_5. They also apply the concept of activation parameters in the mechanistic interpretation of a chemical reaction and learn how to estimate the W-Cg0 bond enthalpy from the experimentally determined enthalpy of activation.