We report on femtosecond (fs) studies of (E)-2-(2-hydroxybenzyliden) amino-4-nitrophenol (HBA-4NP) in dichloromethane (DCM) and triacetin (TAC) solutions, and within NaX and NaY zeolites. In solution, an ultrafast (<= 80 fs) excited-state intramolecular proton-transfer (ESIPT) reaction produces a keto (K) tautomer, which undergoes a rotational process in similar to 4 (DCM) and similar to 7 ps (TAC) toward the formation of non-emitting structures. Within NaX and NaY, where monomers and aggregates are formed, host-guest and guest-guest interactions play an important role in the ultrafast behaviour of these complexes. These results clearly reflect how nanoconfinement and zeolite composition affect the encapsulated dye photodynamics. (C) 2017 Elsevier B.V. All rights reserved.