Fig. 4: Double-difference TRIR spectroscopy of the multipolar compounds.
From: Solvent tuning of photochemistry upon excited-state symmetry breaking
a Vibrational double-difference TRIR contour maps of O in the non-polar cyclohexane and of O and Q in the polar tetrahydrofuran (THF). Excited-state absorption bands are in red and marked with numbers (see text), ground-state bleach is in blue. The time axis is linear between 0 and 1 ps and logarithmic afterwards. Color bars indicate the dominant processes taking place over the specified timespan: symmetry breaking (SB, green), reaction (rxn, blue) or intersystem crossing (ISC, purple). b Evolution-associated double-difference spectra obtained from global analysis of the corresponding data shown in a assuming a consecutive A → B → C → D → reaction scheme.
