Hydrogen atom transfer rates from Tp-containing metal-hydrides to trityl radicals

The H center dot transfer rate constants for a series of group 6 molybdenum and tungsten pyrazolyl borate complexes are described. The rate constants for these complexes were found to span a range over 1 magnitude. Analysis of the H center dot transfer rate constants suggests that a combination of steric, electronic, and enthalpic factors are important in these reactions. Further analysis of the components suggests that the generated 17 e(-) radicals of these complexes are less electrophilic than the more commonly used CpCr(CO)(3)H complexes. General implications for H center dot transfer reactions are discussed.

Automated summary

The H center dot transfer rate constants of a series of group 6 molybdenum and tungsten pyrazolyl borate complexes were studied, showing a wide range of rate constants spanning over 1 magnitude. Analysis indicated that a combination of steric, electronic, and enthalpic factors are important in these reactions, and the generated 17 e(-) radicals of these complexes are less electrophilic compared to CpCr(CO)(3)H complexes. General implications for H center dot transfer reactions were discussed.