Dispersive first-order reactions. I. Data analysis

We present an algorithm which is capable of resolving the spectrum of rates for decay kinetics whose elementary processes follow a first-order law. The stability of the results are illustrated via Monte Carlo analysis of the statistics when trying to reconstruct complex multi-modal distributions of the rates. Additionally, we document the successful application to experimental data for a photochromic isomerization reaction in a polymeric matrix, which allows for acquiring severl thousands of points in time at a noise level of ≤0.1% for the normalized absorption signal. For the first time, different cis-trans conformations of the transient merocyanine species are shown to have distinct kinetic behaviours regarding the decolouration process without biasing the decay analysis.