Comment on the use of linear free-energy slopes as criteria for distinguishing hydride-ion from hydrogen-atom transfer in reactions of pyridine-nucleotide coenzymes.
For reductions by dihydropyridines, the slopes of plots of log k vs the standard reduction potential of the dihydropyridine are not direct indicators of whether the rate-determining step is hydride-ion or hydrogen-atom transfer. When there is no substituent effect on the reverse rate, those slopes are independent of mechanism and equal to about (30mV)-1.
D004579:Electron Transport; D004735:Energy Transfer; D006859:Hydrogen; D007700:Kinetics; D008433:Mathematics; D009243:NAD; D010084:Oxidation-Reduction; D013816:Thermodynamics
D009243:NAD; D006859:Hydrogen