The function of silicon dioxide colloids in photoinduced redox reactions. Interfacial effects on the quenching, charge separation, and quantum yields

1981 ◽  
Vol 85 (22) ◽  
pp. 3277-3282 ◽  
Author(s):  
I. Willner ◽  
Jer-Ming Yang ◽  
Colja Laane ◽  
John W. Otvos ◽  
Melvin Calvin
Keyword(s):  
Silicon Dioxide ◽  
Charge Separation ◽  
Redox Reactions ◽  
Quantum Yields ◽  
Interfacial Effects

scholarly journals Insights into a rutile/brookite homojunction of titanium dioxide: separated reactive sites and boosted photocatalytic activity

RSC Advances ◽  
2019 ◽  
Vol 9 (63) ◽  
pp. 36615-36620 ◽  
Author(s):  
Jing Chen ◽  
Meili Guan ◽  
Xuan Zhang ◽  
Xuezhong Gong
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Charge Separation ◽  
Redox Reactions ◽  
Separation Efficiency ◽  
Charge Separation Efficiency

Reactive sites for redox reactions were spatially separated using a rutile/brookite homojunction, thus contributing to improved charge separation efficiency.

ChemInform Abstract: Photoinitiated Charge Separation in a Carotenoid-Porphyrin-Diquinone Tetrad: Enhanced Quantum Yields via Multistep Electron Transfers.

ChemInform ◽  
1988 ◽  
Vol 19 (15) ◽  
Author(s):  
D. GUST ◽  
T. A. MOORE ◽  
A. L. MOORE ◽  
D. BARRETT ◽  
L. O. HARDING ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Yields ◽  
Electron Transfers

Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad: enhancement of quantum yields via control of electronic coupling

1993 ◽  
Vol 176 (2-3) ◽  
pp. 321-336 ◽  
Author(s):  
Seung-Joo Lee ◽  
Janice M. DeGraziano ◽  
Alisdair N. Macpherson ◽  
Eun-Ju Shin ◽  
Pamela K. Kerrigan ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Yields ◽  
Electronic Coupling ◽  
Photoinduced Charge Separation ◽  
Photoinduced Charge

Photoinitiated charge separation in a carotenoid-porphyrin-diquinone tetrad: enhanced quantum yields via multistep electron transfers

1988 ◽  
Vol 110 (1) ◽  
pp. 321-323 ◽  
Author(s):  
Devens. Gust ◽  
Thomas A. Moore ◽  
Ana L. Moore ◽  
Donna. Barrett ◽  
Larry O. Harding ◽  
...  
Keyword(s):  
Charge Separation ◽  
Quantum Yields ◽  
Electron Transfers

Synthesis, electrochemical, photovoltaic, and photo-physical properties on the lanthanide(III) complexes of acetylacetonate and meso-tetraalkyltetrabenzoporphyrin with electric-field induction

2004 ◽  
Vol 08 (10) ◽  
pp. 1187-1195 ◽  
Author(s):  
Ming-Hui Qi ◽  
Guo-Fa Liu
Keyword(s):  
Electric Field ◽  
Redox Reactions ◽  
Soret Band ◽  
Luminescence Spectroscopy ◽  
Quantum Yields ◽  
Surface Photovoltage ◽  
Absorption Bands ◽  
Photovoltaic Properties ◽  
Surface Photovoltage Spectroscopy ◽  
Spectral Bands

Lanthanide(III) complexes with acetylacetonate and meso-tetraalkyltetrabenzoporphyrin (TATBP) having the general formula Ln ( TATBP )acac (where Ln = Tb , Dy , Ho , Er , Tm , Yb ; A = C 12 H 25; Hacac = acetylacetone) are reported. These compexes have been studied by elemental analyses, ultraviolet visible spectra, infrared spectra, molar conductance, 1 H NMR spectra, cyclic voltammetry, surface photovoltage spectroscopy (SPS), and luminescence spectroscopy. The infrared spectral bands of the ligand and complexes were assigned. In dimethylformamide (DMF), 0.1 M tetrabutylammonium perchlorate (TBAP), the synthesized TATBP exhibit two one-electron reversible redox reactions, and Ln(TATBP)acac shows three redox reactions respectively, within the accessible potential window of the solvent. The absorption bands of the complexes appear in the range 431-433 (Soret band), 578-580 (Q band) and 627-631 (Q band) nm. The photovoltaic properties and charge transfer process of these compounds were investigated by surface photovoltage spectroscopy (SPS) and electric-field-induced surface photovoltage spectroscopy (EFISPS) techniques, which reveal that the ligand TATBP and the complexes Er(TATBP)acac are p-type semiconductors. The spectral bands of TATBP correspond to π → π* transitions. Quantum yields of the S 1 → S 0 fluorescence are in the region 0.25-0.27 and the fluorescence lifetimes are in the region 0.014-0.022 ms at room temperature. The phosphorescence bands of the complex at 77 K appears 714 nm.

Raising the barrier for photoinduced DNA charge injection with a cyclohexyl artificial base pair

2015 ◽  
Vol 185 ◽  
pp. 105-120 ◽  
Author(s):  
Arunoday P. N. Singh ◽  
Michelle A. Harris ◽  
Ryan M. Young ◽  
Stephen A. Miller ◽  
Michael R. Wasielewski ◽  
...  
Keyword(s):  
Base Pair ◽  
Charge Separation ◽  
Charge Recombination ◽  
Hole Injection ◽  
Quantum Yields ◽  
Base Pairs ◽  
Dna Hairpins ◽  
Synthetic Dna ◽  
Photoinduced Charge Separation ◽  
Photoinduced Charge

The effects of an artificial cyclohexyl base pair on the quantum yields of fluorescence and dynamics of charge separation and charge recombination have been investigated for several synthetic DNA hairpins. The hairpins possess stilbenedicarboxamide, perylenediimide, or naphthalenediimide linkers and base-paired stems. In the absence of the artificial base pair hole injection into both adenine and guanine purine bases is exergonic and irreversible, except in the case of stilbene with adenine for which it is slightly endergonic and reversible. Insertion of the artificial base pair renders hole injection endergonic or isoergonic except in the case of the powerful naphthalene acceptor for which it remains exergonic. Both hole injection and charge recombination are slower for the naphthalene acceptor in the presence of the artificial base pair than in its absence. The effect of an artificial base pair on charge separation and charge recombination in hairpins possessing stilbene and naphthalene acceptor linkers and a stilbenediether donor capping group has also been investigated. In the case of the stilbene acceptor–stilbene donor capped hairpins photoinduced charge separation across six base pairs is efficient in the absence of the artificial base pair but does not occur in its presence. In the case of the naphthalene acceptor–stilbene donor capped hairpins the artificial base pair slows but does not stop charge separation and charge recombination, leading to the formation of long-lived charge separated states.

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