Exploring the Ultrafast Excited-State Intramolecular Proton Transfer (ESIPT) of β-Diketones in the deep-UV
نویسندگان
چکیده
The photodynamics in symmetric and unsymmetric β-diketones are studied with transient absorption in the deep-UV. Excitation leads to ultrafast ESIPT while further relaxation and isomerization processes depend on the molecular symmetry and solvent environment. OCIS codes: (320.7150) Ultrafast spectroscopy; (300.6540) Spectroscopy, ultraviolet; (190.7110) Ultrafast nonlinear optics
منابع مشابه
Monitoring ultrafast intramolecular proton transfer processes in an unsymmetric β-diketone.
We report the experimental determination of the intramolecular enol-enol tautomerization rate of an unsymmetric β-diketone, benzoylacetone, with femtosecond transient absorption in the ultraviolet. Initially, there is an equilibrium of two possible enolic structures in solution, which is disturbed upon UV excitation by exciting a disproportionate fraction of one enolic form. Comparison to symme...
متن کاملExcited-state intramolecular proton transfer of 2-acetylindan-1,3-dione studied by ultrafast absorption and fluorescence spectroscopy.
We employ transient absorption from the deep-UV to the visible region and fluorescence upconversion to investigate the photoinduced excited-state intramolecular proton-transfer dynamics in a biologically relevant drug molecule, 2-acetylindan-1,3-dione. The molecule is a ß-diketone which in the electronic ground state exists as exocyclic enol with an intramolecular H-bond. Upon electronic excita...
متن کاملMolecular Seesaw: How Increased Hydrogen Bonding Can Hinder Excited-State Proton Transfer.
A previously unexplained effect in the relative rate of excited-state intramolecular proton transfer (ESIPT) in related indole derivatives is investigated using both theory and experiment. Ultrafast spectroscopy [ J. Phys. Chem. A, 2015, 119, 5618-5625 ] found that although the diol 1,3-bis(2-pyridylimino)-4,7-dihydroxyisoindole exhibits two equivalent intramolecular hydrogen bonds, the ESIPT r...
متن کاملThe photophysics of salicylic acid derivatives in aqueous solution
J. Phys. Or es (SADs) in aqueous solutions was investigated in a wide range of pH by time-correlated single photon counting (lex1⁄4 350nm, tresp1⁄4 300ps) and fluorescence up-conversion (lex1⁄4 266nm, tresp1⁄4 300 fs) techniques. The acid–base equilibrium constants in the ground (pKa) and the excited states (pK a ), the fluorescence quantum yields as well as the lifetimes of anionic, neutral, a...
متن کاملUltrafast excited state hydrogen atom transfer in salicylideneaniline driven by changes in aromaticity.
We investigated two important unresolved issues on excited state intramolecular proton transfer (ESIPT) reactions, i.e., their driving force and the charge state of the transferred species by means of quantum chemical topology. We related changes in the aromaticity of a molecule after electron excitation to reaction dynamics in an excited state. Additionally, we found that the conveyed particle...
متن کامل