Spin-forbidden reactions

In chemistry, the selection rule formally restricts certain reactions, known as spin-forbidden reactions, from occurring due to a required change between two differing quantum states. When a reactant exists in one spin state and the product exists in a different spin state, the corresponding reaction will have an increased activation energy when compared to a similar reaction in which the spin states of the reactant and product are isomorphic. As a result of this increased activation energy, a decreased rate of reaction is observed.


In chemistry, the selection rule formally restricts certain reactions, known as spin-forbidden reactions, from occurring due to a required change between two differing quantum states. When a reactant exists in one spin state and the product exists in a different spin state, the corresponding reaction will have an increased activation energy when compared to a similar reaction in which the spin states of the reactant and product are isomorphic. As a result of this increased activation energy, a decreased rate of reaction is observed.
Read article on Wikipedia