Fig. 2: Ultrafast vibrational fingerprinting demonstrated for a model system.
From: Probing the heterogeneous structure of eumelanin using ultrafast vibrational fingerprinting
Solutions of catechol (Cat) and quinone (Quin) mixtures in cyclohexane contain either a non-interacting, isolated molecules, or b molecules interacting through intermolecular hydrogen bonds. The Cat:Quin mole ratios were fixed at 5:1. a, b Chemical structures of Cat and Quin. c, d UV-vis spectra of cyclohexane solutions of Cat, Quin, and their mixtures, highlighting the excitation wavelengths used in time-resolved infrared (TRIR) spectroscopy experiments. The cell pathlengths used in c and d were 1 mm and 200 μm, respectively. e, f TRIR spectra of the mixture solutions averaged from 1–2 ps, recorded at the indicated excitation wavelengths. g, h Inverted FTIR spectra of cyclohexane solutions of Cat, Quin, and their mixtures.
