Surface photochemistry: Semiconductor mediated reactions of some saturated strained hydrocarbons

1988 ◽  
Vol 66 (7) ◽  
pp. 1579-1588 ◽  
Author(s):  
N. Colin Baird ◽  
Anthony M. Draper ◽  
Paul de Mayo
Keyword(s):  
Electron Transfer ◽  
Quantum Yield ◽  
Transfer Process ◽  
Radical Cations ◽  
Thermal Reaction ◽  
Electron Transfer Process ◽  
Electron Transfer Mechanism ◽  
Valence Isomerization ◽  
Back Electron Transfer

Quadricyclane (1) and 1,8-bishoniocubane (2) have been found to undergo valence isomerization to norborndiene and tricyclo[4.2.2.02,5]deca-3,7-diene, respectively, on illuminated CdS and ZnO. An electron transfer mechanism is proposed. Quantum yield, solvent effects, the role of oxygen, and the quenching of the reaction were investigated, and were consistent with this interpretation. The thermal reaction of 1 on CdS was also suggested to be an electron transfer process involving, in this case, defects or trapped holes on the surface of the semiconductor. An examination of a series of strained hydrocarbons structurally related to 1 (tetracyclo[3.3.0.02,8.04,6]octane 3, pentacyclo[4.3.0.02,4.03.805,7]nonane 4 and pentacyclo[4.4.0.02,4.03,8.05,7]decane 5) resulted, largely, in a demonstration of the resistance of their respective radical cations to rearrangement prior to back electron transfer. Calculations by MNDO, in combination with a modified version of MM2, were used to explore the differences in the reactivity of the radical cations of 1, 3, 4, 5, and an interpretation is presented.

Thionine–graphene oxide covalent hybrid and its interaction with light

2017 ◽  
Vol 19 (22) ◽  
pp. 14412-14423 ◽  
Author(s):  
Ewelina Krzyszkowska ◽  
Justyna Walkowiak-Kulikowska ◽  
Sven Stienen ◽  
Aleksandra Wojcik
Keyword(s):  
Electron Transfer ◽  
Graphene Oxide ◽  
Excited State ◽  
Transfer Process ◽  
Singlet Excited State ◽  
Functionalized Graphene ◽  
Electron Transfer Process ◽  
Functionalized Graphene Oxide ◽  
Back Electron Transfer

Quenching of the thionine singlet excited state in covalently functionalized graphene oxide with an efficient back electron transfer process.

scholarly journals Two-electron transfer stabilized by excited-state aromatization

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinseok Kim ◽  
Juwon Oh ◽  
Seongchul Park ◽  
Jose L. Zafra ◽  
Justin R. DeFrancisco ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Excited States ◽  
Transfer Process ◽  
Comprehensive Understanding ◽  
Electron Transfer Process ◽  
Photoactive Materials ◽  
Donor Acceptor ◽  
Scientific Significance

Abstract The scientific significance of excited-state aromaticity concerns with the elucidation of processes and properties in the excited states. Here, we focus on TMTQ, an oligomer composed of a central 1,6-methano[10]annulene and 5-dicyanomethyl-thiophene peripheries (acceptor-donor-acceptor system), and investigate a two-electron transfer process dominantly stabilized by an aromatization in the low-energy lying excited state. Our spectroscopic measurements quantitatively observe the shift of two π-electrons between donor and acceptors. It is revealed that this two-electron transfer process accompanies the excited-state aromatization, producing a Baird aromatic 8π core annulene in TMTQ. Biradical character on each terminal dicyanomethylene group of TMTQ allows a pseudo triplet-like configuration on the 8π core annulene with multiexcitonic nature, which stabilizes the energetically unfavorable two-charge separated state by the formation of Baird aromatic core annulene. This finding provides a comprehensive understanding of the role of excited-state aromaticity and insight to designing functional photoactive materials.

scholarly journals Deciphering the incognito role of water in a light driven proton coupled electron transfer process

2018 ◽  
Vol 9 (4) ◽  
pp. 910-921 ◽  
Author(s):  
Senthil Kumar Thiyagarajan ◽  
Raghupathy Suresh ◽  
Vadivel Ramanan ◽  
Perumal Ramamurthy
Keyword(s):  
Electron Transfer ◽  
Proton Transfer ◽  
Transfer Process ◽  
Electron Transfer Process ◽  
Solvent Water ◽  
Proton Coupled Electron Transfer ◽  
Electron Proton Transfer ◽  
Role Of Solvent ◽  
Proton Transfer Process

The incognito role of solvent water as a proton transfer bridge in a multi-site electron proton transfer process was depicted.

The central role of ligands in electron transfer from perovskite nanocrystals

MRS Advances ◽  
2017 ◽  
Vol 2 (43) ◽  
pp. 2327-2335 ◽  
Author(s):  
Alberto Privitera ◽  
Marcello Righetto ◽  
Renato Bozio ◽  
Lorenzo Franco
Keyword(s):  
Electron Transfer ◽  
Transfer Process ◽  
Photoinduced Electron Transfer ◽  
Fullerene Derivative ◽  
Mixed Solution ◽  
Electron Transfer Process ◽  
Perovskite Nanocrystals ◽  
Pulsed Epr ◽  
Photoinduced Processes

ABSTRACTThe nanoscale miniaturization of hybrid organic-inorganic perovskite has given rise to new functionalities, but the full understanding of the multifaceted properties of perovskite nanostructures is still incomplete. Using a combination of optical and magnetic resonance (EPR) spectroscopies, we focused our investigation on the photoinduced electron transfer process taking place in perovskite nanocrystals blended with the fullerene derivative PCBM. In particular we analyzed the different effect of two types of nanocrystal ligands, namely octylamine and oleylamine, on the photoinduced processes. The electron transfer process resulted in efficient fluorescence quenching in a mixed solution and in the formation of charges (PCBM anions) detected by EPR in the blends. Both the optical and EPR techniques revealed a stronger effect when the shorter ligand is present. Finally, pulsed EPR demonstrated the stabilization of the photogenerated charges in proximity of perovskite nanocrystals.

Photo-induced dual passivation via Usanovich acid–base on surface defects of methylammonium lead triiodide perovskite

2018 ◽  
Vol 20 (44) ◽  
pp. 28068-28074 ◽  
Author(s):  
Yue Yu ◽  
Sushu Wan ◽  
Daocheng Hong ◽  
Yuxi Tian
Keyword(s):  
Electron Transfer ◽  
Transfer Process ◽  
Surface Defects ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Acid Base ◽  
Photoluminescence Quenching ◽  
Electron Transfer Process ◽  
Electron Transfer Mechanism ◽  
Defect Sites

Usanovich acid–base (O2, acetone or acetonitrile) treatment can effectively passivate photoluminescence quenching defects in MAPbI3 perovskite by single-electron transfer mechanism. This electron transfer process allows the defect sites to function as photo-catalysts.

scholarly journals Electron transfer process in microbial electrochemical technologies: The role of cell-surface exposed conductive proteins

2018 ◽  
Vol 255 ◽  
pp. 308-317 ◽  
Author(s):  
Nazua L. Costa ◽  
Thomas A. Clarke ◽  
Laura-Alina Philipp ◽  
Johannes Gescher ◽  
Ricardo O. Louro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Cell Surface ◽  
Transfer Process ◽  
Electron Transfer Process
Sign in / Sign up

Export Citation Format

Share Document