Analyzing experimental UV-vis spectra of conjugated molecules in solution: Pekarian function fit

Abstract

We present a modified version of the Pekarian function (PF) suitable for fitting of UV-vis absorption and fluorescence spectra. This function can be applied to fit organic conjugated compound spectra in solution with high accuracy and reproducibility, via optimization of five parameters that define the band shape for both vibronically resolved and unresolved bands. Three examples of spectra involving overlapping bands and requiring one to three PFs are presented in detail. Fitting of spectra can be performed using commercial PeakFit or Origin software (with user-defined functions provided) or through a homemade PekarFit Python script.