Effects of DNA on driving force dependence of photoinduced electron transfer from the excited state of tris(2,2-bipyridine)ruthenium(II) to intercalators in DNA

A donor-σ-acceptor compound incorporating tetrathiafulvalene and tetraphenylporphyrin units was synthesized. The structures of the target compound and its intermediates have been characterized by 1 H NMR, ESI MS, UV-vis, IR and mp. The results of UV-vis and cyclic voltammetry of the compound indicated negligible intramolecular charge transfer interaction in its ground state. The fluorescence and fluorescence lifetime of the compound were reduced, compared to tetraphenylporphyrin, which evidently indicated that photoinduced electron transfer occurred from the tetrathiafulvalene (TTF) unit to the tetraphenylporphyrin unit in the excited state. The fluorescence intensity of the compound could be reversibly modulated by sequential oxidation and reduction of the TTF unit using electrochemical and chemical methods. Therefore, a new fluorescence molecular switch based on TTF and porphyrin units was established.

Download Full-text

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.11.234 ◽

2015 ◽

Vol 11 ◽

pp. 2166-2170

Author(s):

Baiba Turovska ◽

Henning Lund ◽

Viesturs Lūsis ◽

Anna Lielpētere ◽

Edvards Liepiņš ◽

...

Keyword(s):

Electron Transfer ◽

Solid State ◽

Light Intensity ◽

Photoinduced Electron Transfer ◽

Driving Force ◽

Spectroscopic Data

Stable heterocyclic hydroperoxide can be easily prepared as a product of fast oxidation of a 1,2,3,4-tetrahydropyridine by 3O2 if the solution is exposed to sunlight. The driving force for the photoinduced electron transfer is calculated from electrochemical and spectroscopic data. The outcome of the reaction depends on the light intensity and the concentration of O2. In the solid state the heterocyclic hydroperoxide is stable; in solution it is involved in further reactions.

Download Full-text

Driving Force Dependent, Photoinduced Electron Transfer at Degenerately Doped, Optically Transparent Semiconductor Nanoparticle Interfaces

Journal of the American Chemical Society ◽

10.1021/ja508862h ◽

2014 ◽

Vol 136 (45) ◽

pp. 15869-15872 ◽

Cited By ~ 34

Author(s):

Byron H. Farnum ◽

Zachary A. Morseth ◽

M. Kyle Brennaman ◽

John M. Papanikolas ◽

Thomas J. Meyer

Keyword(s):

Electron Transfer ◽

Photoinduced Electron Transfer ◽

Driving Force ◽

Semiconductor Nanoparticle ◽

Optically Transparent ◽

Transparent Semiconductor

Download Full-text

Solvatochromic and Ligand Effects in Ultrafast Intramolecular Electron Transfer in Fe-based Molecular Photosensitizers

EPJ Web of Conferences ◽

10.1051/epjconf/201920509029 ◽

2019 ◽

Vol 205 ◽

pp. 09029

Author(s):

Kristjan Kunnus ◽

Lin Li ◽

Marco Reinhard ◽

Sergey Koroidov ◽

Kasper S. Kjaer ◽

...

Keyword(s):

Electron Transfer ◽

Excited State ◽

Charge Transfer ◽

Driving Force ◽

Reorganization Energy ◽

The Other ◽

Intramolecular Electron Transfer ◽

Ligand Effects ◽

Ligand Charge Transfer ◽

Excited State Lifetimes

Metal-to-ligand charge-transfer (MLCT) excited state lifetimes of [Fe(CN)4(2,2’-bipyridine)]2- and [Fe(CN)4(2,3-bis(2-pyridyl)pyrazine)]2-exhibit strong solvent and ligand dependence. We conclude that these effects can be described with Marcus-like model where changes in the MLCT energy correspond directly to the changes in the electron transfer driving force and all the other factors (e.g. reorganization energy) can be considered constant.

Download Full-text