title: Influence of intermolecular hydrogen bonding on the photochromic cycle of the aromatic Schiff base N,N'-bis(salicylidene)-p-phenylenediamine in solution.
abstract: A photochromic symmetric Schiff base, N,N'-bis(salicylidene)-p-phenylenediamine, has been studied by means of stationary and time-resolved spectroscopic absorption and emission techniques in the UV-vis spectral range with particular attention to the role of intermolecular hydrogen bonds. They are found to be responsible for the solvent-assisted excited-state proton transfer (the time constant of about 400 fs) in very strongly protic solvents and the photochrome deactivation (the time constant from 0.5 micros to 3 ms) in both protic and nonprotic solvents. Moreover, formation of an isomer that competes with the photochromic cycle in solution is also observed.
authors.affiliation: Center for Ultrafast Laser Spectroscopy, and Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland. marziol@amu.edu.pl
authors.forename: Marcin
authors.initials: M
authors.lastname: Ziółek
authors.forename: Gotard
authors.initials: G
authors.lastname: Burdziński
authors.forename: Jerzy
authors.initials: J
authors.lastname: Karolczak