meso-Arylethynyl subporphyrins as efficient and tunable photo-induced electron transfer units

2017 ◽  
Vol 21 (02) ◽  
pp. 152-157 ◽  
Author(s):  
Won-Young Cha ◽  
Juwon Oh ◽  
Masaaki Kitano ◽  
Atsuhiro Osuka ◽  
Dongho Kim
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Fluorescence Quenching ◽  
Charge Separation ◽  
Solvent Polarity ◽  
Enhanced Fluorescence ◽  
Excited State Dynamics ◽  
Photo Induced Electron Transfer

Excited state dynamics of meso-arylethynyl-substituted subporphyrins can be tuned by 4-substituent at the arylethynyl group and solvent polarity. In polar acetonitrile, phenylethynyl subporphyrin 1 exhibited enhanced fluorescence, while (4-dimethylaminophenyl)ethynyl subporphyrin 2 showed red-shifted fluorescence from its charge-separated state and (4-nitrophenyl)ethynyl subporphyrin 3 displayed efficient fluorescence quenching due to charge separation.

Excited state dynamics and electron transfer in a phosphorus(V) porphyrin – TEMPO conjugate

2021 ◽  
Vol 133 (3) ◽  
Author(s):  
PRASHANTH K PODDUTOORI ◽  
NOAH HOLZER ◽  
BRANDON J BAYARD ◽  
YURI E KANDRASHKIN ◽  
GARY LIM ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Excited State Dynamics

scholarly journals Photoinduced Interactions in a Pyrene-Calix[4]arene-Perylene Bisimide Dye System: Probing Ground-State Conformations with Excited-State Dynamics of Charge Separation and Recombination

2009 ◽  
Vol 113 (42) ◽  
pp. 18358-18368 ◽  
Author(s):  
Nguyen Vân Anh ◽  
Felix Schlosser ◽  
Michiel M. Groeneveld ◽  
Ivo H. M. van Stokkum ◽  
Frank Würthner ◽  
...  
Keyword(s):  
Excited State ◽  
Ground State ◽  
Charge Separation ◽  
Excited State Dynamics ◽  
Perylene Bisimide

Donor-acceptor conjugates derived from cobalt porphyrin and fullerene via metal-ligand axial coordination: Formation and excited state charge separation

2021 ◽  
pp. A-N
Author(s):  
Dili R. Subedi ◽  
Youngwoo Jang ◽  
Ashwin Ganesan ◽  
Sydney Schoellhorn ◽  
Ryan Reid ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Separation ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Cobalt Porphyrin ◽  
Axial Coordination ◽  
Cobalt Porphyrins ◽  
Donor Acceptor ◽  
Metal Ligand

Two types of cobalt porphyrins, viz., meso-tetrakis(tolylporphyrinato)cobalt(II), (TTP)Co (1), and meso-tetrakis(triphenylamino porphyrinato)cobalt(II), [(TPA)4P]Co, (2) were self-assembled via metal-ligand axial coordination of phenyl imidazole functionalized fulleropyrrolidine, ImC[Formula: see text] to form a new series of donor–acceptor constructs. A 1:2 complex formation with ImC[Formula: see text] was established in the case of (TTP)Co while for [(TPA)4P]Co only a 1:1 complex was possible to positively identify. The binding constants [Formula: see text] and [Formula: see text] for step-wise addition of ImC[Formula: see text] to (TTP)Co were found to be 1.07 × 105 and 3.20 × 104 M[Formula: see text], respectively. For [(TPA)4P]Co:ImC[Formula: see text], the measured [Formula: see text] values was found to be 6.48 × 104 M[Formula: see text], slightly smaller than that observed for (TTP)Co. Although both cobalt porphyrins were non-fluorescent, they were able to quench the fluorescence of ImC[Formula: see text] indicating occurrence of excited state events in the supramolecular donor-acceptor complexes. Electrochemistry coupled with spectroelectrochemistry, revealed the formation of cobalt(III) porphyrin cation instead of a cobalt(II) porphyrin radical cation, as the main product, during oxidation of phenyl imidazole coordinated cobalt porphyrin. With the help of computational and electrochemical results, an energy level diagram was constructed to witness excited state photo-events. Competitive energy and electron transfer from excited CoP to coordinated ImC[Formula: see text], and electron transfer from Im1C[Formula: see text]* to cobalt(II) porphyrin resulting into the formation of PCo[Formula: see text]:ImC[Formula: see text] charge separated state was possible to envision from the energy diagram. Finally, using femtosecond transient absorption spectroscopy and data analysis by Glotaran, it was possible to establish sequential occurrence of energy transfer and charge separation processes. The lifetime of the final charge separated state was [Formula: see text] 2 ns. A slightly better charge stabilization was observed in the case of [(TPA)4P]Co:ImC[Formula: see text] due to the presence of electron rich, peripheral triphenylamine substituents on the cobalt porphyrin.

The electron that breaks the catalyst’s back – excited state dynamics in intermediates of molecular photocatalysts

2021 ◽  
Author(s):  
Carolin Müller ◽  
Ilse Friedländer ◽  
Benedikt Bagemihl ◽  
Sven Rau ◽  
Benjamin Dietzek
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Single Electron ◽  
Intramolecular Electron Transfer ◽  
Excited State Dynamics ◽  
Transfer Processes ◽  
Electron Reduction ◽  
Electron Transfer Processes ◽  
Franck Condon

In situ spectroelectrochemical studies focussing on the Franck-Condon region and sub-ns electron transfer processes in Ru(II)-tpphz-Pt(II) based photocatalysts reveal that single-electron reduction effectively hinders intramolecular electron transfer between the photoexcited...

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