Computer-aided chemistry IV: fast fourier transform analysis of luminescence decay curves using a desk top microcomputer

Abstract

An improved analytical procedure, which uses a fast Fourier transform (FFT) algorithm, has been developed to deconvolute luminescence decay curves. Using this procedure, the non-exponential fluorescence decay curves recorded from the excited singlet state of magnesium tetraphenylporphyrin in the presence of CBr₄ in frozen solution, in which both radiative transfer and electron transfer quench the excited state, have been examined. This procedure eliminates the common “overlap effect” that is inherent in previous uses of FFT methods when applied to the problem of deconvoluting decay curves, through a systematic reconstruction of the input data. The analysis may be performed either in the time domain or in the frequency domain. An interactive program, DECAYFIT, written in Fortran 77 was used to carry out the calculations on the IBM S9001 laboratory microcomputer. The program can be employed to deconvolute both model test data and real data, with a time for the analysis in the range of minutes.