Photoinduced electron transfer in a directly linked meso-triphenylamine zinc porphyrin-quinone dyad

2011 ◽  
Vol 15 (05n06) ◽  
pp. 391-400 ◽  
Author(s):  
Channa A. Wijesinghe ◽  
Marja Niemi ◽  
Nikolai V. Tkachenko ◽  
Navaneetha K. Subbaiyan ◽  
Melvin E. Zandler ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Free Energy Calculations ◽  
Excitation Wavelength ◽  
Triplet States ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Porphyrin Macrocycle ◽  
Donor Acceptor ◽  
Donor Ability

A multimodular donor-acceptor system composed of three triphenylamine entities at the meso-positions of a zinc porphyrin macrocycle and a quinone at the fourth meso-position was newly synthesized and characterized. The triphenylamine entities acted as energy transferring antenna units in addition of improving the electron donor ability of the zinc porphyrin. Appreciable electronic interactions of the triphenylamine and quinone entities with the porphyrin π-system were observed. In agreement with the spectral and electrochemical results, the computational studies performed by the DFT B3LYP/3-21G(*) method revealed delocalization of the frontier HOMO over the triphenylamine and the porphyrin macrocycle while the LUMO to be fully localized over the quinone entity. Free-energy calculations suggested photoinduced electron transfer from the singlet excited zinc porphyrin to the directly linked quinone to be exothermic and this was experimentally confirmed by the time-resolved pump probe and up-conversion techniques. In the investigated system, the ET reaction path was found to depend upon the excitation wavelength. That is, when Zn porphyrin was predominantly excited, a rapid charge separation followed by equally fast charge recombination was observed. However, excitation of the peripheral TPA substituents resulted in an extremely long-lived CS state with triplet spin character via the TPA triplet and Zn porphyrin triplet states.

Photoinduced electron transfer through hydrogen bonds in a rod-like donor–acceptor molecule: A time-resolved EPR study

2006 ◽  
Vol 324 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Manuela Jakob ◽  
Alexander Berg ◽  
Eli Stavitski ◽  
Erin T. Chernick ◽  
Emily A. Weiss ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Bonds ◽  
Photoinduced Electron Transfer ◽  
Acceptor Molecule ◽  
Time Resolved ◽  
Donor Acceptor

REVERSIBLE, METASTABLE, ULTRAFAST PHOTOINDUCED ELECTRON TRANSFER FROM SEMICONDUCTING POLYMERS TO BUCKMINSTERFULLERENE AND IN THE CORRESPONDING DONOR/ACCEPTOR HETEROJUNCTIONS

1994 ◽  
Vol 08 (03) ◽  
pp. 237-274 ◽  
Author(s):  
N. S. SARICIFTCI ◽  
A. J. HEBGER
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Ground State ◽  
Charge Separation ◽  
Photoinduced Electron Transfer ◽  
Semiconducting Polymers ◽  
Time Resolved ◽  
Degenerate Ground State ◽  
Photoinduced Charge Separation ◽  
Donor Acceptor

The results of comprehensive studies of photoinduced electron transfer from semiconducting (conjugated) polymers to buckminsterfullerene are reviewed. Steady state and femtosecond time-resolved photoinduced absorption (photoexcitation spectroscopy), steady state and picosecond time-resolved photoluminescence, steady state and picosecond photoconductivity, and steady state light-induced electron spin resonance measurements are summarized as experimental evidence which demonstrates ultrafast, long lived photoinduced electron transfer. Comparative studies with different semiconducting polymers as donors demonstrate that in degenerate ground state polymers, soliton excitations form before the electron transfer can occur; thereby inhibiting charge transfer and charge separation. In non-degenerate ground state systems, photoinduced electron transfer occurs in less than 10−12 s , quenching the photoluminescence as well as the intersystem crossing into the triplet manifold. The importance of electron–phonon coupling and structural relaxation following photoexcitation in these quasi-one-dimensional semiconducting polymers is proposed as a principal contribution to the stabilization of the charge separated state. Utilizing thin films of the semiconducting polymer (donor) and buckminsterfullerene (acceptor) to form a heterojunction interface, we have fabricated bilayers which functioned as photodiodes and as photovoltaic cells. The results are discussed in terms of opportunities for solar energy conversion, for photodiode detector devices, and for a variety of other applications which use photoinduced charge separation.

Photoinduced electron-transfer processes between phthalocyanines and perylene derivatives

2006 ◽  
Vol 10 (10) ◽  
pp. 1190-1196 ◽  
Author(s):  
Koji Kitazume ◽  
Yu Chen ◽  
Mitsunari Itou ◽  
Yasuyuki Araki ◽  
Satoshi Uchida ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Transient Absorption ◽  
Triplet States ◽  
Intermolecular Electron Transfer ◽  
Absorption Bands ◽  
Time Resolved ◽  
Transfer Processes ◽  
Perylene Derivatives ◽  
Electron Transfer Processes

Photoinduced electron-transfer processes between phthalocyanines ( H2Pc and ZnPc ) as electron donors and perylene derivatives as electron acceptors have been studied using a time-resolved, nanosecond transient absorption method in benzonitrile. The observed findings show that intermolecular electron transfer takes place via the excited triplet states of ZnPc and H2Pc , as confirmed by the characteristic transient absorption bands in the near-IR region. The visible light excitation of the mixtures of H2Pc and the perylene derivatives adsorbed onto TiO2gave a relatively high photovoltaic efficiency.

Photoinduced Electron Transfer within a Zinc Porphyrin-Cyclobis(paraquat-p-phenylene) Donor-Acceptor Dyad

2014 ◽  
Vol 20 (45) ◽  
pp. 14690-14697 ◽  
Author(s):  
Maher Fathalla ◽  
Jonathan C. Barnes ◽  
Ryan M. Young ◽  
Karel J. Hartlieb ◽  
Scott M. Dyar ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Zinc Porphyrin ◽  
Donor Acceptor

Photoelectrochemical properties of supramolecular composites of an anionic zinc chlorin and Li+@C60 on SnO2

2014 ◽  
Vol 18 (10n11) ◽  
pp. 982-990 ◽  
Author(s):  
Kei Ohkubo ◽  
Yuki Kawashima ◽  
Kentaro Mase ◽  
Hayato Sakai ◽  
Taku Hasobe ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Photovoltaic Cells ◽  
Lithium Ion ◽  
Transparent Electrode ◽  
Supramolecular Complex ◽  
Photoelectrochemical Properties ◽  
Triplet Excited State ◽  
Optically Transparent ◽  
Donor Acceptor

An electron donor–acceptor supramolecular complex was formed between an anionic zinc chlorin carboxylate ( ZnCh -) and lithium-ion-encapsulated [60]fullerene ( Li +@ C 60) by an electrostatic interaction in benzonitrile ( PhCN ). Photoinduced electron transfer in the supramolecular complex of ZnCh -/ Li +@ C 60 resulted in the formation of the charge-separated state via electron transfer from the triplet excited state of ZnCh - to Li +@ C 60. We report herein photovoltaic cells using ZnCh -/ Li +@ C 60 nanoclusters, which are assembled on the optically transparent electrode (OTE) of nanostructured SnO 2 (OTE/ SnO 2). The photoelectrochemical behavior of the nanostructured SnO 2 film of supramolecular nanoclusters of ZnCh - and Li +@ C 60 denoted as OTE/ SnO 2/( ZnCh -/ Li +@ C 60)n is significantly higher than the single component films of ZnCh - or Li +@ C 60 clusters, denoted as OTE/ SnO 2/( ZnCh -)n or OTE/ SnO 2/( Li +@ C 60)n.

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