Minimum electrophilicity principle: an analysis based upon the variation of both chemical potential and absolute hardness.

In this work, the minimum electrophilicity principle (MEP), assessed by either the electrophilicity power or the DeltaNmax, is mathematically analysed through the variation of both chemical potential and chemical hardness. It appears that the decrease of the electrophilicity power and the decrease of the DeltaNmax are ruled by similar expressions in which both the chemical potential and the absolute hardness should increase. A reduced expression at constant chemical potential shows that the MEP and the maximum hardness principle are equivalent. However it pops up from the monitoring of chemical processes such as bond formation and redox reactions that the variation of the chemical potential is the most important term.