What is the activated complex in a chemical reaction?

The activated complex, also known as the transition state, is a temporary, unstable arrangement of atoms that occurs at the peak of the potential energy barrier during a chemical reaction. This state represents a crucial moment where reactants are in the process of breaking and forming bonds to transition into products. At this point, the system has maximum potential energy, and the atoms are in a high-energy configuration.

The instability of the activated complex is key, as it quickly breaks down to form products or revert back to reactants, which is why it cannot be isolated for observation. In this context, understanding the dynamics of the activated complex is vital in the study of reaction mechanisms and rates, as it plays a critical role in how reactants transform into products through the overcoming of energy barriers.