In addition to being used as ligands in metal complexes, olefins have also been found to form important intermediates with various metals in the catalysis of many metal-catalyzed reactions. Therefore, understanding the bonding between the metal and olefin in these metal-olefin complexes is crucial in the effort to increase their efficiency. Measuring the activation parameters for the bond dissociation of metal-cyanoethylenes was performed to determine whether the binding of the ligand is via eta1 (through the nitrogen) or eta2 (through the double bond). Computational modeling predicts that the metal-olefin bond favors the eta1 bonding mode over the eta 2 mode. Kinetic studies were carried out using a scheme in which pyridine was used to compete with fumaronitrile (trans-1,2-dicyanoethene) during thermally induced decomposition of the complex X(CO)5-(fumaronitrile) (X= Cr, Mo, or W) in toluene solution. The kinetics was interpreted under a dissociative mechanism, in which the rate determining step is the dissociation of fumaronitrile from the metal complex. An Eyring analysis of the temperature dependence of the rate constant for the dissociation of fumaronitrile from the X(CO)5-(fumaronitrile) complex was used to obtain the enthalpy and entropy of activation of the thermal decomposition of these complexes.

Determining the activation enthalpy and entropy of the thermal decomposition of X(CO)<sub>5</sub>-fumaronitrile (X= Cr, Mo, or W)

247th National Meeting (2014)

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Determining the activation enthalpy and entropy of the thermal decomposition of X(CO)5-fumaronitrile (X= Cr, Mo, or W)

Determining the activation enthalpy and entropy of the thermal decomposition of X(CO)₅-fumaronitrile (X= Cr, Mo, or W)