For 25 simple reactions, the changes of the hardness (△η), polarizability (△α) and electrophilicity index (△ω) and their cube-roots (△η^1/3, △α^1/3, △ω^1/3) were calculated. It is shown that althou...For 25 simple reactions, the changes of the hardness (△η), polarizability (△α) and electrophilicity index (△ω) and their cube-roots (△η^1/3, △α^1/3, △ω^1/3) were calculated. It is shown that although the Maximum Hardness and Minimum Polarizability Principles are not valid for all reactions, but in most cases △ω^1/3〈0, whereas we always find △ω〈0. Our observation implies to this fact that for those chemical reactions in which the number of moles decreases or at least remains constant, the most stable species (reactants or products) have the lowest sum of electrophilicities. In other words "the natural direction of a chemical reaction is toward a state of minimum electrophilicity". This fact may be called Minimum Electrophilicity Principle (MEP).展开更多
文摘For 25 simple reactions, the changes of the hardness (△η), polarizability (△α) and electrophilicity index (△ω) and their cube-roots (△η^1/3, △α^1/3, △ω^1/3) were calculated. It is shown that although the Maximum Hardness and Minimum Polarizability Principles are not valid for all reactions, but in most cases △ω^1/3〈0, whereas we always find △ω〈0. Our observation implies to this fact that for those chemical reactions in which the number of moles decreases or at least remains constant, the most stable species (reactants or products) have the lowest sum of electrophilicities. In other words "the natural direction of a chemical reaction is toward a state of minimum electrophilicity". This fact may be called Minimum Electrophilicity Principle (MEP).