scholarly journals An electron transfer driven magnetic switch: ferromagnetic exchange and spin delocalization in iron verdazyl complexes

2018 ◽  
Vol 47 (18) ◽  
pp. 6351-6360 ◽  
Author(s):  
David J. R. Brook ◽  
Connor Fleming ◽  
Dorothy Chung ◽  
Cardius Richardson ◽  
Servando Ponce ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Spin Crossover ◽  
Large Change ◽  
Single Electron ◽  
Spin Multiplicity ◽  
Magnetic Switch ◽  
Ferromagnetic Exchange ◽  
Spin Delocalization ◽  
Electron Reduction

A single electron reduction of an iron bis(verdazyl) complex results in a large change in spin multiplicity resulting from a combination of spin crossover and exceptionally strong ferromagnetic exchange.

scholarly journals Correction: An electron transfer driven magnetic switch: ferromagnetic exchange and spin delocalization in iron verdazyl complexes

2018 ◽  
Vol 47 (24) ◽  
pp. 8164-8164
Author(s):  
David J. R. Brook ◽  
Connor Fleming ◽  
Dorothy Chung ◽  
Cardius Richardson ◽  
Servando Ponce ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Magnetic Switch ◽  
Dalton Trans ◽  
Ferromagnetic Exchange ◽  
Spin Delocalization

Correction for ‘An electron transfer driven magnetic switch: ferromagnetic exchange and spin delocalization in iron verdazyl complexes’ by David J. R. Brook et al., Dalton Trans., 2018, 47, 6351–6360.

The electron that breaks the catalyst’s back – excited state dynamics in intermediates of molecular photocatalysts

2021 ◽  
Author(s):  
Carolin Müller ◽  
Ilse Friedländer ◽  
Benedikt Bagemihl ◽  
Sven Rau ◽  
Benjamin Dietzek
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Single Electron ◽  
Intramolecular Electron Transfer ◽  
Excited State Dynamics ◽  
Transfer Processes ◽  
Electron Reduction ◽  
Electron Transfer Processes ◽  
Franck Condon

In situ spectroelectrochemical studies focussing on the Franck-Condon region and sub-ns electron transfer processes in Ru(II)-tpphz-Pt(II) based photocatalysts reveal that single-electron reduction effectively hinders intramolecular electron transfer between the photoexcited...

Electrochemical and in situ spectroelectrochemical behavior of 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H2OHTTAP) and [Zn(II)OHTTAP]

2001 ◽  
Vol 05 (06) ◽  
pp. 523-527 ◽  
Author(s):  
YANXIU ZHOU ◽  
ZHENXING WANG ◽  
DAIKE WANG ◽  
KENICHI SUGIURA ◽  
YOSHITERU SAKATA
Keyword(s):  
Electron Transfer ◽  
Differential Pulse ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Free Base ◽  
Cation Radicals ◽  
Pulse Voltammetry ◽  
Electron Reduction

The characterization of free base porphyrin 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H2OHTTAP) and its zinc(II) complexes [ Zn (II)OHTTAP] containing eight thioether groups at the β-pyrrole positions of the macrocycle was reported. Results obtained by cyclic voltammetry and differential pulse voltammetry indicated a five-electron reduction in five steps for each complex. They were oxidized in two single-electron-transfer steps to yield π-cation radicals and dications and reduced in three single-electron-transfer steps to yield π-anion radicals, dianions and trianions, respectively. The redox property of H2OHTTAP was unusual as compared to porphyrins (PPs) and phthalocyanines (Pcs). Each process was monitored by in situ thin-layer spectroelectrochemistry, which indicated that only the ligand was electroactive. The existence of the eight hexylthio groups was responsible for the intrastack interactions and enhanced intracolumnar and intercolumnar electron motions, resulting in improved conductivity.

scholarly journals Single metal four-electron reduction by U(II) and masked “U(II)” compounds

2021 ◽  
Author(s):  
Marinella Mazzanti ◽  
Rosario Scopelliti ◽  
Maron Laurent ◽  
Iskander Douair ◽  
Chad Palumbo ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Redox Chemistry ◽  
Single Electron ◽  
Transfer Reactions ◽  
Single Electron Transfer ◽  
Electron Transfer Reactions ◽  
Element Chemistry ◽  
Electron Reduction ◽  
Electron Transfers

The redox chemistry of uranium is dominated by single electron transfer reactions while single metal four-electron transfers remain unknown in f-element chemistry. Here we show that the oxo bridged diuranium(III)...

scholarly journals Single-electron reduction of quinone and nitroaromatic xenobiotics by recombinant rat neuronal nitric oxide synthase.

2013 ◽  
Vol 60 (2) ◽  
Author(s):  
Žilvinas Anusevičius ◽  
Henrikas Nivinskas ◽  
Jonas Šarlauskas ◽  
Marie-Agnes Sari ◽  
Jean-Luc Boucher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Electron Transfer ◽  
Nitric Oxide Synthase ◽  
Neuronal Nitric Oxide Synthase ◽  
Outer Sphere ◽  
Transfer Mechanism ◽  
Single Electron ◽  
Electron Transfer Mechanism ◽  
Electron Reduction ◽  
Oxide Synthase

We examined the kinetics of single-electron reduction of a large number of structurally diverse quinones and nitroaromatic compounds, including a number of antitumour and antiparasitic drugs, and nitroaromatic explosives by recombinant rat neuronal nitric oxide synthase (nNOS, EC 1.14.13.39), aiming to characterize the role of nNOS in the oxidative stress-type cytotoxicity of the above compounds. The steady-state second-order rate constants (kcat/Km) of reduction of the quinones and nitroaromatics varied from 10² M⁻¹s⁻¹ to 10⁶ M⁻¹s⁻¹, and increased with an increase in their single-electron reduction potentials (E¹₇). The presence of Ca²⁺/calmodulin enhanced the reactivity of nNOS. These reactions were consistent with an 'outer sphere' electron-transfer mechanism, considering the FMNH∙/FMNH₂ couple of nNOS as the most reactive reduced enzyme form. An analysis of the reactions of nNOS within the 'outer sphere' electron-transfer mechanism gave the approximate values of the distance of electron transfer, 0.39-0.47 nm, which are consistent with the crystal structure of the reductase domain of nNOS. On the other hand, at low oxygen concentrations ([O₂] = 40-50 μM), nNOS performs a net two-electron reduction of quinones and nitroaromatics. This implies that NOS may in part be responsible for the bioreductive alkylation by two-electron reduced forms of antitumour aziridinyl-substituted quinones under a modest hypoxia.

scholarly journals The special role of B(C6F5)3 in the single electron reduction of quinones by radicals

2018 ◽  
Vol 9 (41) ◽  
pp. 8011-8018 ◽  
Author(s):  
Xin Tao ◽  
Constantin G. Daniliuc ◽  
Robert Knitsch ◽  
Michael Ryan Hansen ◽  
Hellmut Eckert ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Radical Anion ◽  
Single Electron ◽  
Special Role ◽  
Single Electron Transfer ◽  
Electron Reduction ◽  
Trityl Cation

In the presence of two molar equiv. of B(C6F5)3p-benzoquinone reacts with persistent radicals TEMPO, trityl or decamethylferrocene by single electron transfer to give the doubly O-borylated benzosemiquinone radical anion with TEMPO+, trityl cation or ferrocenium counter cations.

Reversal of Polarity by Catalytic SET Oxidation: Synthesis of Azabicyclo[m.n.o]alkanes via Chemoselective Reduction of Amidines

2021 ◽  
Author(s):  
Sundarababu Baskaran ◽  
Kirana D V ◽  
Kanak Kanti Das
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Catalytic Method ◽  
One Pot ◽  
Oxidative System ◽  
Oxidation Synthesis

A one-pot catalytic method has been developed for the stereoselective synthesis of cyclopropane-fused cyclic amidines using CuBr2/K2S2O8 as an efficient single electron transfer (SET) oxidative system. The generality of this...

scholarly journals Autocatalytic photoredox Chan-Lam coupling of free diaryl sulfoximines with arylboronic acids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cong Wang ◽  
Hui Zhang ◽  
Lucille A. Wells ◽  
Tian Liu ◽  
Tingting Meng ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom Abstraction ◽  
Coupling Reactions ◽  
Ambient Light ◽  
Environmental Friendliness ◽  
Copper Species ◽  
Arylboronic Acids ◽  
Ligand Free ◽  
Byproduct Formation ◽  
Electron Reduction

AbstractN-Arylation of NH-sulfoximines represents an appealing approach to access N-aryl sulfoximines, but has not been successfully applied to NH-diaryl sulfoximines. Herein, a copper-catalyzed photoredox dehydrogenative Chan-Lam coupling of free diaryl sulfoximines and arylboronic acids is described. This neutral and ligand-free coupling is initiated by ambient light-induced copper-catalyzed single-electron reduction of NH-sulfoximines. This electron transfer route circumvents the sacrificial oxidant employed in traditional Chan-Lam coupling reactions, increasing the environmental friendliness of this process. Instead, dihydrogen gas forms as a byproduct of this reaction. Mechanistic investigations also reveal a unique autocatalysis process. The C–N coupling products, N-arylated sulfoximines, serve as ligands along with NH-sulfoximine to bind to the copper species, generating the photocatalyst. DFT calculations reveal that both the NH-sulfoximine substrate and the N-aryl product can ligate the copper accounting for the observed autocatalysis. Two energetically viable stepwise pathways were located wherein the copper facilitates hydrogen atom abstraction from the NH-sulfoximine and the ethanol solvent to produce dihydrogen. The protocol described herein represents an appealing alternative strategy to the classic oxidative Chan-Lam reaction, allowing greater substrate generality as well as the elimination of byproduct formation from oxidants.

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