Intramolecular proton transfer of a 2-(2′,4′-dinitrobenzyl)pyridine studied by femtosecond transient absorption spectroscopy

The photochromic intramolecular proton transfer in 2-(2′,4′-dinitrobenzyl)pyridine was investigated by femtosecond pump–probe transient absorption spectroscopy. Three different transient absorption spectra were observed depending on the delay time between the pump and probe beams. Based on the analysis of the observed spectra, the reaction time of the intramolecular proton transfer of this material was estimated to be 320∼500 fs.