Binding and reactivity under restricted geometry conditions: Applicability of the Pseudophase Model to thermal and photochemical processes

Reactivity under restricted geometry conditions can be quantitatively rationalized by using the Pseudophase Model. This model considers two states in equilibrium, free and bound, which are not perturbed by the reaction. That is, the reaction in which the two states participate must be slow in comparison to the exchange process between the free and bound states. This condition is fulfilled in the case of chemical reactions, but it does not hold for fast photochemical reactions. In spite of this, the Pseudo-phase Model was found to be, at least apparently, applicable for excited state reactions. However, a thorough analysis of the kinetic data brings to light important differences between the two types of reactions, particularly in the meaning of the parameters present in the equations of the Pseudophase Model. (C) 2017 Elsevier Ltd. All rights reserved.