Breaking aggregation in a tetrathiafulvalene-fused zinc porphyrin by metal–ligand coordination to form a donor–acceptor hybrid for ultrafast charge separation and charge stabilization

2015 ◽  
Vol 44 (1) ◽  
pp. 359-367 ◽  
Author(s):  
Atanu Jana ◽  
Habtom B. Gobeze ◽  
Masatoshi Ishida ◽  
Toshiyuki Mori ◽  
Katsuhiko Ariga ◽  
...  
Keyword(s):  
Charge Separation ◽  
Electrochemical Methods ◽  
Zinc Porphyrin ◽  
Ligand Coordination ◽  
Donor Acceptor ◽  
Metal Ligand ◽  
Charge Stabilization

A novel electron rich, tetrathiafulvalene fused zinc porphyrin, (TTF)4PZn, has been newly synthesized and characterized using spectral and electrochemical methods.

Multi-modular, tris(triphenylamine) zinc porphyrin–zinc phthalocyanine–fullerene conjugate as a broadband capturing, charge stabilizing, photosynthetic ‘antenna-reaction center’ mimic

Nanoscale ◽  
2015 ◽  
Vol 7 (15) ◽  
pp. 6813-6826 ◽  
Author(s):  
Chandra B. KC ◽  
Gary N. Lim ◽  
Francis D'Souza
Keyword(s):  
Electron Transfer ◽  
Reaction Center ◽  
Zinc Phthalocyanine ◽  
Zinc Porphyrin ◽  
Donor Acceptor ◽  
Photosynthetic Antenna ◽  
Charge Stabilization

Charge stabilization as a result of electron transfer followed by a hole-shift mechanism is demonstrated in a supramolecular multi-modular donor–acceptor assembly.

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.

scholarly journals Charge stabilization via electron exchange: excited charge separation in symmetric, central triphenylamine derived, dimethylaminophenyl–tetracyanobutadiene donor–acceptor conjugates

2021 ◽  
Author(s):  
Indresh S. Yadav ◽  
Ajyal Z. Alsaleh ◽  
Rajneesh Misra ◽  
Francis D'Souza
Keyword(s):  
Charge Separation ◽  
Electron Exchange ◽  
Donor Acceptor ◽  
Charge Stabilization

The significance of electron exchange in stabilizing the charge-separated state is revealed in multi-modular donor–acceptor conjugates.

scholarly journals Self-Assembled Nanomaterials Based on Complementary Sn(IV) and Zn(II)-Porphyrins, and Their Photocatalytic Degradation for Rhodamine B Dye

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim
Keyword(s):  
Aqueous Solution ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Self Assembly ◽  
The Self ◽  
Assembly Process ◽  
Absorption Bands ◽  
Ligand Coordination ◽  
Rhodamine B Dye ◽  
Metal Ligand

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.

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