Activated Complex vs Transition State | Transition Complex vs Activation Complex
When one or more reactants are converting to products, they may go through different modifications and energy changes. The chemical bonds in the reactants are breaking, and new bonds are forming to generate products, which are totally different from the reactants. This chemical modification is known as chemical reactions. There are numerous variables controlling the reactions. For a reaction to take place, there should be required energy. Reactant molecules go through changes throughout the reaction assuming various atomic configurations. Activated complex and transitions state are two terminologies used to identify these intermediate complexes and most of the time these two terms are used interchangeably.
What is Activated complex?
A molecule must be activated before they can undergo reaction. Molecules normally do not have much energy with them, only occasionally some molecules are in an energy state to undergo reactions. Where there are two reactants, for the reaction to happen, the reactants must collide with each other in the proper orientation. Although reactants just encounter one another, most encounters are not leading to a reaction. These observations have given the idea of having an energy barrier to reactions. The reactants with higher energy states in the reaction mixture can be considered as activated complexes. Not all the activated complexes may go to the products, they can be fallen back to reactants if they do not have enough energy.
What is Transition State?
Transition state is thought of one in which the reacting molecule is strained or distorted or has an unfavorable electronic configuration. The molecule must pass through this high-energy transition state before reaction is to occur. The energy gap is known as activation energy. This is the highest energy barrier for a reaction to take place. If the activation for a reaction is too high, only a small fraction of molecules will have enough energy to surmount it, so the expected products concentration will not be obtained. The atomic arrangement of all the molecules in the reaction, which has the activation energy, is called the transition complex. Transition complex has components with partially broken bonds and partially made new bonds. Therefore, it has partial negative and positive charges. Transition state is shown with a double dagger sign (‡). If the transition state energy of a reaction can be lowered, then the reaction should be much faster and will require low energy to proceed. For an exothermic reaction, following is the energy curve.
What is the difference between activated complex and transition state?
• Transition state is the atomic arrangement with the highest energy when reactants are going to products. Activated complexes are all the other configurations in the reaction pathway, which have higher energy than normal molecules.
• There is a high possibility of a transition state complex to go to the products. However, activation complexes can fall back to form reactants than going to the products.