scholarly journals Photoinduced charge accumulation by metal ion-coupled electron transfer

2015 ◽  
Vol 17 (37) ◽  
pp. 24001-24010 ◽  
Author(s):  
Annabell G. Bonn ◽  
Oliver S. Wenger
Keyword(s):  
Electron Transfer ◽  
Lewis Acid ◽  
Metal Ion ◽  
Lewis Base ◽  
Charge Accumulation ◽  
Superoxide Anions ◽  
Strong Lewis Acid ◽  
Photoinduced Charge

Strong Lewis acid/Lewis base interactions between Sc3+and superoxide anions permit the light-driven accumulation of two positive charges on oligotriarylamine units with appended Ru(ii) photosensitizers.

scholarly journals Photoinduced electron transfer in a molecular dyad by nanosecond pump–pump–probe spectroscopy

2018 ◽  
Vol 17 (7) ◽  
pp. 903-909 ◽  
Author(s):  
M.-H. Ha-Thi ◽  
V.-T. Pham ◽  
T. Pino ◽  
V. Maslova ◽  
A. Quaranta ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Charge Accumulation ◽  
Pump Probe ◽  
Probe Spectroscopy ◽  
Photoinduced Charge

Photoinduced charge accumulation was investigated in a molecular dyad composed of a porphyrin chromophore and a ruthenium-based catalyst by pump–pump–probe experiments.

[Cr(ttpy)2]3+ as a multi-electron reservoir for photoinduced charge accumulation

2019 ◽  
Vol 48 (20) ◽  
pp. 6800-6811 ◽  
Author(s):  
Rajaa Farran ◽  
Long Le-Quang ◽  
Jean-Marie Mouesca ◽  
Vincent Maurel ◽  
Damien Jouvenot ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
Tertiary Amine ◽  
Visible Light Irradiation ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Light Irradiation ◽  
Charge Accumulation ◽  
Photoinduced Charge

Under visible light irradiation [Cr(ttpy)2]3+ can be reduced twice by a tertiary amine; the photoreduction processes are accelerated in the presence of [Ru(bpy)3]2+ acting as an antenna thanks to an efficient electron transfer reaction from [Ru(bpy)3]2+* to [Cr(ttpy)2]3+.

scholarly journals Colloidal CdSe nanocrystals are inherently defective

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tamar Goldzak ◽  
Alexandra R. McIsaac ◽  
Troy Van Voorhis
Keyword(s):  
Charge Transfer ◽  
Energy Spectrum ◽  
Surface Structure ◽  
Short Range ◽  
Surface Defects ◽  
Low Energy ◽  
Lewis Base ◽  
Cdse Nanocrystals ◽  
Photoinduced Charge Transfer ◽  
Photoinduced Charge

AbstractColloidal CdSe nanocrystals (NCs) have shown promise in applications ranging from LED displays to medical imaging. Their unique photophysics depend sensitively on the presence or absence of surface defects. Using simulations, we show that CdSe NCs are inherently defective; even for stoichiometric NCs with perfect ligand passivation and no vacancies or defects, we still observe that the low energy spectrum is dominated by dark, surface-associated excitations, which are more numerous in larger NCs. Surface structure analysis shows that the majority of these states involve holes that are localized on two-coordinate Se atoms. As chalcogenide atoms are not passivated by any Lewis base ligand, varying the ligand should not dramatically change the number of dark states, which we confirm by simulating three passivation schemes. Our results have significant implications for understanding CdSe NC photophysics, and suggest that photochemistry and short-range photoinduced charge transfer should be much more facile than previously anticipated.

A universal approach for optimizing charge extraction in electron transporting layer-free organic solar cells via Lewis base doping

2019 ◽  
Vol 7 (45) ◽  
pp. 25808-25817
Author(s):  
Rong Wang ◽  
Boxin Wang ◽  
Jianqiu Wang ◽  
Xuning Zhang ◽  
Dongyang Zhang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Photovoltaic Device ◽  
Lewis Base ◽  
Device Performance ◽  
Universal Approach ◽  
Electron Transporting Layer ◽  
Charge Extraction ◽  
Base Doping

Applying anion-induced electron transfer doping with a series of TXABr salts to non-fullerene organic solar cells enables to tune the doping efficiency and photovoltaic device performance.

New insights about the host–guest chemistry of the tungsten oxo complex of calix[4]arene, and novel "one pot" difunctionalizations of calix[4]arene using tetrachlorometal(VI) oxide (M = Mo, W)

2004 ◽  
Vol 82 (10) ◽  
pp. 1452-1461 ◽  
Author(s):  
Pascal Mongrain ◽  
Jasmin Douville ◽  
Jonathan Gagnon ◽  
Marc Drouin ◽  
Andreas Decken ◽  
...  
Keyword(s):  
Water Molecule ◽  
Lewis Acid ◽  
Chemical Shifts ◽  
Strong Interactions ◽  
Ir Absorption ◽  
One Pot ◽  
X Ray ◽  
Strong Lewis Acid ◽  
Successful Removal ◽  
Coordinated Water

The strong Lewis acid tungsten oxo complex of calix[4]arene can be obtained in both hydrated and non-hydrated forms. This complex coordinates a water molecule inside the cavity via strong O···W interactions with relatively short distances of 2.284(4) and 2.329(2) Å for the tungsten oxo complex of calix[4]arene··H2O·aniline (1), and the tungsten oxo complex of calix[4]arene·H2O·toluene (2·toluene), respectively. The strong interactions are also deduced by the relatively high H2O elimination temperature observed by TGA and DSC (above 200 °C). The coordinated water molecule inside the calix[4]arene cavity is characterized by a strong IR absorption at 3616 cm–1, and a narrow resonance at ~1.2 ppm (the chemical shifts of the uncoordinated water are 1.55 and 1.60 ppm in C6D6 and CDCl3, respectively). This water molecule gives rise to H-bonds with aniline in 1. The tungsten oxo complex of 5,11,17,23-tetrabromocalix[4]arene (4), also binds H2O as the characteristic signatures are observed. The successful removal of H2O in 2, is performed under mild conditions using bis(tetrahydrofuran)-uranyl nitrate as a competitive Lewis acid. When this reaction is performed in acetonitrile, butyronitrile or tert-butylnitrile, the corresponding tungsten oxo complexes of calix[4]arene·acetonitrile (3), ·butyronitrile (5), and ·tert-butylnitrile (6) are obtained. The use of uranyl as a H2O abstractor is unprecedented. The X-ray structure of 3 consists of a tungsten oxo complex of calix[4]arene coordinated by an acetonitrile molecule (d(W···N = 2.412(2) Å). The tetra-5,11,17,23-choromethyl-25,26,27,28-tetrahydroxycalix[4]arene reacts with M(O)Cl4 (M = Mo, W) in a 1:1 stoichiometry, via a tetra Friedel–Crafts addition of benzene or toluene, followed by a lower-rim complexation of the metal oxide, to form "flower-shaped" calix[4]arenes. This "one pot" double functionalization is unprecedented.Key words: calix[4]arene, tungsten, molybdenum, X-ray, host–guest, Friedel–Crafts, Lewis acid, uranyl, DSC, TGA.

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