Contributions to the spectroscopic-kinetic analysis of linear reaction systems - Systems with three linearly independent reactions using the concept of parallel projection

Linear reaction systems consist by definition of first-order reaction steps . Linearly independent reactions are independent of reaction order. Each re action mechanism consists of a distinct number (s) of Linearly independent reaction steps. Thus, the mechanism A reversible arrow B reversible arrow C reversible arrow D can be described by three linearly independent reaction s as it is also true for A --> B --> C --> D (s = 3). In the following, a p rocedure for the analysis of linear reaction systems consisting of three li nearly independent reaction steps is described which is based on absorbance (A) as well as absorbance difference quotient (ADQ) diagrams (two graphs o f the 'Mauser diagrams') and the concept of parallel projection. In this wa y it is possible to determine the ratio of eigenvalues describing the react ion mechanism. Furthermore, the reaction system (s = 3) can be reduced to a system which is described only by two Linearly independent concentration v ariables (s = 2). The kinetic equations of evaluation are simplified by the concept of parallel projection. This can be helpful, for example, when one independent reaction step shows poor spectroscopic properties. The method can be extended to the analysis of quasilinear photoreactions. The method i s demonstrated using a practical example (A' --> B', C' --> D', E' --> F'). (C) 1999 Elsevier Science B.V. All rights reserved.