title: Substituent and solvent effects on the excited state deactivation channels in anils and boranils.
abstract: Differently substituted anils (Schiff bases) and their boranil counterparts lacking the proton-transfer functionality have been studied using stationary and femtosecond time-resolved absorption, fluorescence, and IR techniques, combined with quantum mechanical modelling. Dual fluorescence observed in anils was attributed to excited state intramolecular proton transfer. The rate of this process varies upon changing solvent polarity. In the nitro-substituted anil, proton translocation is accompanied by intramolecular electron transfer coupled with twisting of the nitrophenyl group. The same type of structure is responsible for the emission of the corresponding boranil. A general model was proposed to explain different photophysical responses to different substitution patterns in anils and boranils. It is based on the analysis of changes in the lengths of CN and CC bonds linking the phenyl moieties. The model allows predicting the contributions of different channels that involve torsional dynamics to excited state depopulation.
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland).
authors.forename: Jacek
authors.initials: J
authors.lastname: Dobkowski
authors.forename: Paweł
authors.initials: P
authors.lastname: Wnuk
authors.forename: Joanna
authors.initials: J
authors.lastname: Buczyńska
authors.forename: Maria
authors.initials: M
authors.lastname: Pszona
authors.forename: Grażyna
authors.initials: G
authors.lastname: Orzanowska
authors.forename: Denis
authors.initials: D
authors.lastname: Frath
authors.forename: Gilles
authors.initials: G
authors.lastname: Ulrich
authors.forename: Julien
authors.initials: J
authors.lastname: Massue
authors.forename: Sandra
authors.initials: S
authors.lastname: Mosquera-Vázquez
authors.forename: Eric
authors.initials: E
authors.lastname: Vauthey
authors.forename: Czesław
authors.initials: C
authors.lastname: Radzewicz
authors.forename: Raymond
authors.initials: R
authors.lastname: Ziessel
authors.forename: Jacek
authors.initials: J
authors.lastname: Waluk
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001895:Boron / Q000737:chemistry*; D007700:Kinetics; D011522:Protons; D012545:Schiff Bases / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: D000814:Aniline Compounds; D011522:Protons; D012545:Schiff Bases; D012997:Solvents; D001895:Boron; C023650:aniline
keywords: anils; boranils; photochemistry; photophysics; ultrafast spectroscopy