Excited-state deactivation mechanisms of protonated and neutral phenylalanine: a theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 29032-29039
Author(s):  
Reza Omidyan ◽  
Mitra Ataelahi ◽  
Gholamhassan Azimi
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Excited States ◽  
Theoretical Study ◽  
Minimum Energy ◽  
Bond Stretching ◽  
Minimum Energy Paths ◽  
Electronic Ground

Minimum energy paths (MEPs) of protonated phenylalanine (PheH+) at the electronic ground and S1 (1ππ*) excited states along the Cα–Cβ bond stretching coordinate, following proton transfer to the aromatic chromophore.

scholarly journals Photoacidity as a tool to rationalize excited state intramolecular proton transfer reactivity in flavonols

2018 ◽  
Vol 17 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Luís Gustavo Teixeira Alves Duarte ◽  
José Carlos Germino ◽  
Cláudia de Ávila Braga ◽  
Cristina Aparecida Barboza ◽  
Teresa Dib Zambon Atvars ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Excited States ◽  
Intramolecular Proton Transfer ◽  
Flavonol Derivatives ◽  
Proton Transfer Reactivity ◽  
Electronic Ground

Determination of acidic strengths at the electronic ground and excited states of flavonol derivatives.

scholarly journals Ingenious modification of molecular structure effectively regulates excited-state intramolecular proton and charge transfer: a theoretical study based on 3-hydroxyflavone

RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29589-29597 ◽  
Author(s):  
Jianhui Han ◽  
Xiaochun Liu ◽  
Chaofan Sun ◽  
You Li ◽  
Hang Yin ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Excited State ◽  
Charge Transfer ◽  
Proton Transfer ◽  
Theoretical Study ◽  
Intramolecular Charge Transfer ◽  
Intramolecular Proton Transfer ◽  
Great Promise ◽  
Fluorescence Sensing

Harnessing ingenious modification of molecular structure to regulate excited-state intramolecular proton transfer (ESIPT) and intramolecular charge transfer (ICT) characteristics holds great promise in fluorescence sensing and imaging.

scholarly journals Excited-State Relaxation in Luminescent Molybdenum(0) Complexes with Isocyanide Chelate Ligands

Inorganics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 14
Author(s):  
Patrick Herr ◽  
Oliver S. Wenger
Keyword(s):  
Excited State ◽  
Excited States ◽  
Quantum Yields ◽  
Nonradiative Relaxation ◽  
Temperature Dependent ◽  
Tert Butyl ◽  
Thermally Activated ◽  
Ligand Charge Transfer ◽  
Order Of Magnitude ◽  
Electronic Ground

Diisocyanide ligands with a m-terphenyl backbone provide access to Mo0 complexes exhibiting the same type of metal-to-ligand charge transfer (MLCT) luminescence as the well-known class of isoelectronic RuII polypyridines. The luminescence quantum yields and lifetimes of the homoleptic tris(diisocyanide) Mo0 complexes depend strongly on whether methyl- or tert-butyl substituents are placed in α-position to the isocyanide groups. The bulkier tert-butyl substituents lead to a molecular structure in which the three individual diisocyanides ligated to one Mo0 center are interlocked more strongly into one another than the ligands with the sterically less demanding methyl substituents. This rigidification limits the distortion of the complex in the emissive excited-state, causing a decrease of the nonradiative relaxation rate by one order of magnitude. Compared to RuII polypyridines, the molecular distortions in the luminescent 3MLCT state relative to the electronic ground state seem to be smaller in the Mo0 complexes, presumably due to delocalization of the MLCT-excited electron over greater portions of the ligands. Temperature-dependent studies indicate that thermally activated nonradiative relaxation via metal-centered excited states is more significant in these homoleptic Mo0 tris(diisocyanide) complexes than in [Ru(2,2′-bipyridine)3]2+.

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