163231-34-3Relevant academic research and scientific papers
Proton-Transfer Processes in Well-Defined Media: Experimental Investigation of Photoinduced and Thermal Proton-Transfer Processes in Single Crystals of 2-(2,4-Dinitrobenzyl)pyridine Derivatives
Scherl, Michael,Haarer, Dietrich,Fischer, Jean,DeCian, Andre,Lehn, Jean-Marie,Eichen, Yoav
, p. 16175 - 16186 (2007/10/03)
A detailed spectroscopic study of photoinduced and thermally activated proton-transfer processes for a series of different crystals of 2-(2,4-dinitrobenzyl)pyridine derivatives has been performed.The quantitative analysis of ground- and excited-state activation barriers and preexponential factors in deuterated and nondeuterated crystals shows clearly that the observed photochromism is linked to a proton-transfer process.Furthermore, it is clearly seen that the supramolecular environment of the transferred proton participates in the proton-transfer process.These supramolecular effects control the relative rates and efficiencies of the observed proton-transfer processes in both the ground and excited state, yielding, at room temperature, photoproducts having lifetimes ranging between hours and weeks.At least two proton-accepting groups may be active in the abstraction of the proton from its relatively stable benzylic position.Additionally, low-temperature measurements of proton-transfer processes show that tunneling processes prevail at temperatures below 100 K only in the excited state.No evidence for tunneling could be found for ground-state processes.
Long-lived Photoinduced Proton Transfer Processes
Eichen, Yoav,Lehn, Jean-Marie,Scherl, Michael,Haarer, Dietrich,Casalegno, Roger,et al.
, p. 713 - 714 (2007/10/02)
Irradiation of the phenanthroline-dinitrobenzyl compound 3 generates, via a photoinduced proton transfer process, a long-lived tautomer having a lifetime about 5*103 times longer than that of the parent compound 1a.
