Negligible shift of 3Ag- potential in longer-chain carotenoids as revealed by a single persistent peak of 3Ag-→1Ag- stimulated emission followed by 3Ag-←1Ag- transient-absorption

The negligible shift of 3Ag- potential can explain how the 3Ag-(υ)→1Ag-(υ) emission and 3Ag-(υ)←1Ag-(υ) absorptive transitions can give rise to a single persistent peak of the 3Ag-(0) energy with no changes in energy and spectral pattern during the vibrational relaxation processes of υ = 2 → 1 → 0, in anhydrorhodovibrin (n = 12).