Fig. 2: Femtosecond transient absoprtion spectroscopy (fs-TA) spectra of the precursor 1 after 267 nm excitation in MeCN.

a normalized- Evolution Associated Difference Spectra (EAS) according to the sequential kinetic models, (b) time evolution of the state population obtained from the global fitting analysis and the color of the fitting trace is consistent with the EAS spectra represented in Fig. 2a, (c) contour plots of the time-resolved absorption spectroscopic responses, (d) comparison of the third EAS spectra obtained in different percentages of water in MeCN, (e) the comparism of the experimental data (bottom) and the calculated UV–vis spectra(top): the 3rd EAS spectrum in Fig. 2a (bottom, red) and the 3rd EAS spectrum in Supplementary Fig. 3 (bottom, black), computed UV-vis spectra of the triplet 4-iodophenylnitrenium ion ³2 (np) (top, red) and closed-shell 4-iodophenylnitrenium ion ¹2 (n²) (top, black) obtained by CASPT2//CASSCF/PCM/cc-pVDZ calculations. The Cartesian Coordinates of the computed structures are shown in the Supplementary Data File.