174286-36-3Relevant academic research and scientific papers
The role of SO2 as a ligand to mediate associative substitution reactions of some 18-electron molybdenum complexes
Shen, Jian Kun,Basolo, Fred,Kubas, Gregory J.
, p. C1 - C3 (2007/10/02)
Results of kinetic studies are reported for intramolecular PPh3 substitution reactions of Mo(CO)2(η1-L)(PPh3)2(SO2) to form Mo(CO)2(η2-L)(PPh3)(SO2) (L = dmpe=(Me)2PC2H4P(Me)2 and dppe=Ph2PC2H4PPh2) in THF as solvent.Activation parameters for the reactions are: ΔH values 12.3 kcal mol-1 for dmpe and 16.7 kcal mol-1 for dppe; and ΔS values -30.3 cal mol-1 K for dmpe and -16.4 cal mol-1 K for dppe.These results are consistent with an intramolecular associative mechanism.The facile associative pathway for the reaction is discussed in terms of the ability of SO2 to accept a pair of electrons from the metal, with a bonding transformation of η2-SO2 to η1-pyramidal SO2, so maintaining a stable 18-electron count for the complex in the transition state.Keywords: Molybdenum; Sulfur dioxide; Ligand substitution; Kinetics; Mechanism
