Search results for "Electron transfer"
showing 10 items of 282 documents
Electronic structure of the glyoxalbis(2-hydroxyanil) (gha) ligand in [CoIII(gha)(PPh3)2]+: radical vs. non-radical states
2008
The synthesis, structure and spectroscopic properties of a complex salt [CoIII(gha)(PPh3)2][CoIICl3(PPh3)]·C2H5OH (1) are reported; gha = glyoxalbis(2-hydroxyanil). This is the first single crystal X-ray structure of a (gha)2− complex with a transition element. Though the determined bond parameters and UV-Vis spectroscopic data correlate well with a diradical description for the cation in 1, detailed electronic structure calculations using density functional theory confirm that [Co(gha)(PPh3)2]+ can be described as a closed shell singlet species which nevertheless displays an interesting electronic structure with significant electron transfer to the formally unoccupied LUMO of the square pl…
Electric Field Control of Spin-Dependent Dissipative Electron Transfer Dynamics in Mixed-Valence Molecules
2015
We demonstrate that the borderline class II/III magnetic MV dimers, which can be referred to as single molecule multiferroics, provide a unique possibility to achieve electric field control of the electron transfer (ET) dynamics. As an example, we consider a MV dimer d2-d1 in which an extra electron is delocalized over two spin-cores (s0 = 1/2), and the ET is spin-dependent due to the double exchange mechanism. It is assumed that the “extra” electron is coupled to the only intramolecular vibration, and a weak coupling to the dissipative subsystem (thermal bath) is taken into account. The vibronic energy levels and the wave functions of the isolated dimer (quantum part of the system) are num…
Computational Screening of Doped Graphene Electrodes for Alkaline CO2 Reduction
2020
The electrocatalytic CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR) is considered as one of the most promising approaches to synthesizing carbonaceous fuels and chemicals without utilizing fossil resources. However, current technologies are still in the early phase focusing primarily on identifying optimal electrode materials and reaction conditions. Doped graphene-based materials are among the best CO<sub>2</sub>RR electrocatalysts and in the present work we have performed a computational screening study to identify suitable graphene catalysts for CO<sub>2</sub>RR to CO under alkaline conditions. Several types of modified-graphene frame…
Fundamentals of photoelectrocatalysis
2022
Photoelectrocatalysis combines heterogeneous photocatalysis and electrocatalysis principles for numerous processes including the degradation of harmful compounds, the generation of H2 and O2 from water splitting, the reduction of CO2 or the photoelectrocatalytic synthesis of valuable organic molecules otherwise difficult to be synthetized with classical approaches. The recent progress of photoelectrocatalysis is heavily related to the development of materials, especially in 2D and nano materials. Highly ordered nanomaterials such as graphene, nanotubes, nanowires, etc. are gaining more attention due to their high surface area and excellent conductivity. Other challenges are the development …
Electrochemical study of copper chloride complexes in the RTIL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide
2013
The electrochemistry of copper(I) and copper(II) chloride complexes in the RTIL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, BMPTf2N, has been studied with constant current electrolysis and cyclic staircase voltammetry at temperatures between 21.0 and 96.0 °C and in different concentrations of chloride. The chloride concentration was controlled by addition of 1-butyl-1-methylpyrrolidinium chloride, BMPCl. An important finding is the evidence of a three-coordinated complex, Cu(I)Cl32− which has not been found in organic chloroaluminates without a significant increase in temperature. Two Cu(I) species were found at molar ratios of [Cl−]/[Cu] < 4. The kinetic parameters for…
Changing the size of a cavity via an electron-transfer: synthesis and reduction of 1,5,22,26-tetraoxa-[5,5]-(2,8)-dibenzo[a,e]cylooctatetraenophane
1989
Abstract The synthesis and electron transfer reactions of the title compound, the first macrocycle incorporating two cyclooctatetraene units, are described.
Poly(naphthalenediimidequaterthiophene):Poly(hexyilthiophene) Heterojunctions. Efficient Polymer-to-Polymer Electron Transfer Interfaces
2013
Organic thin films solar cells and plastic solar cells [1] have attracted the attention of the scientific community especially as regards the performance of new conjugated polymers including their interfaces [2-4]. In this work, poly(naphthalenediimidequaterthiophene) (PNDIT4) and poly(hexyilthiophene) (P3HT) have been employed, for the first time, for engineering planar and bulk heterojunctions by the synergetic use of two techniques: electropolymerization and layer by layer deposition. Electropolymerization has been used for obtaining PNDIT4 thin films on transparent ITO/PET electrodes, starting from the synthesized monomer. Inverse Langmuir-Schaefer technique has been employed for deposi…
Transient absorption studies of the Ru(dcbpy)2(NCS)2 excited state and the dye cation on nanocrystalline TiO2 film
2001
We have measured dynamics of the Ru(dcbpy)2(NCS)2 [dcbpy = 4,4′-dicarboxy-2,2′-bipyridine] excited state and the dye cation on nanocrystalline TiO2 film in the wavelength region 700–900 nm. The dye in ethanol solution and Ru(dcbpy)2(NCS)2 sensitized nanocrystalline Al2O3 films were used as non-injecting reference samples for excited state identification. For TiO2/Ru(dcbpy)2(NCS)2 film the `reactant' decay and `product' formation kinetics observed at different probe wavelengths showed that the resolved transient absorption picosecond components (1.1±0.2), (12±2) and (100±5) ps are related to electron injection from the excited states of the dye to the semiconductor TiO2.
Photocatalytic behavior of mixed WO3/WS2 powders
2000
Polycrystalline mixed WO3/WS2 powders have been prepared by different methods. The samples have been characterized by bulk and surface techniques and tested as catalysts for the photodegradation of phenol. The results have indicated that the coupling of WO3 and WS2 leads to an enhanced rate of disappearance of the organic substrate. The effect is explained as the result of the simultaneous electron transfer from WS2 to WO3 and hole transfer from WO3 to WS2. The efficiency of the mixed WO3/WS2 systems strongly depends on the relative amounts of WO3 and WS2 in the various samples. A maximum of photoactivity is obtained when the surface WS2 and WO3 molar fraction is about 0.5.