scholarly journals Optimization of Photocatalyst Excited- and Ground-State Reduction Potentials for Dye-Sensitized HBr Splitting

2018 ◽  
Vol 10 (37) ◽  
pp. 31312-31323 ◽  
Author(s):  
Matthew D. Brady ◽  
Ludovic Troian-Gautier ◽  
Renato N. Sampaio ◽  
Tyler C. Motley ◽  
Gerald J. Meyer
Keyword(s):  
Ground State ◽  
State Reduction ◽  
Dye Sensitized ◽  
Reduction Potentials

Correlation of 13C and 15N nuclear magnetic resonance chemical shifts with polarographic reduction potentials of para-substituted benzenediazonium salts and their electronic structures

1984 ◽  
Vol 62 (1) ◽  
pp. 92-95 ◽  
Author(s):  
R. M. Elofson ◽  
N. Cyr ◽  
J. K. Laidler ◽  
K. F. Schulz ◽  
F. F. Gadallah
Keyword(s):  
Ground State ◽  
Electronic Structures ◽  
Chemical Shifts ◽  
Linear Increase ◽  
Polarographic Reduction ◽  
Single Bond ◽  
Reduction Potentials ◽  
Linear Relationships ◽  
Half Wave ◽  
Absorption Frequencies

Carbon-13 and nitrogen-15 nmr chemical shifts of benzenediazonium salt and its para-substituted derivatives have been measured in sulfolane solutions. The chemcial shifts of 13C1 correlate linearly with the polarographic half-wave potentials. This relation indicates the linear increase of electron densities at C1 with the increase of electron-donating power of the substituents. Non-linear relationships between 15N shifts of both nitrogen nuclei and the half-wave potentials were partly attributed to the second-order paramagnetic contributions to the 15N shifts. This contribution is approximately proportional to the inverse of the uv absorption frequencies. Overall results suggest that in the ground state resonance structures of the benzenediazonium salts, the rehybridization of the C1—N1 bond is very unlikely and this bond remains as a single bond.

scholarly journals A DFT Study on the Redox Active Behavior of Carbene and Pyridine Ligands in the Oxidative and Reductive Quenching Cycles of Ruthenium Photoredox Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 80
Author(s):  
Edinson Medina ◽  
Balazs Pinter
Keyword(s):  
Density Functional ◽  
Interaction Analysis ◽  
Photon Absorption ◽  
Redox Potentials ◽  
State Reduction ◽  
Covalent Interaction ◽  
Reduction Potentials ◽  
Pyridine Ligands ◽  
Redox Active ◽  
Characteristic Features

In this study, a detailed look at the electronic structure changes induced by photon absorption and of the succeeding redox events of the oxidative and reductive quenching cycles of ruthenium–carbene and ruthenium–pyridine photoredox catalysts is provided through an arsenal of density functional theory-based techniques including electron density difference Δρ(r) maps, spin-density distributions, and the non-covalent interaction analysis. We introduced an efficient computational protocol to obtain accurate equilibrium structures and ground-state reduction potentials for these types of complexes, substantiated via a direct comparison to empirical X-ray structures and cyclic voltammetry measurements, respectively. Moreover, we demonstrated the utility of a hitherto unexplored approach to compute excited-state redox potentials based on the Gibbs free energy of the triplet metal-to-ligand charge transfer state (3MLCT). The analyzed Δρ(r) maps revealed the characteristic features of, for example, metal- and ligand-centered reductions and oxidations in both ground and excited states and MLCT processes, disclosing the active participation of carbene ligands in the redox events of homoleptic systems. Beyond analyzing ligand–ligand non-covalent interactions and redox-active behaviors of carbene and pyridine ligands side by side, the effect of such groups on the kinetics of 3MLCT to 3MC transition was scrutinized.

DFT/TD-DFT Studies on the Lawsone (Henna) as a Photosensitizer for Dye-Sensitized Solar Cells

2015 ◽  
Vol 789-790 ◽  
pp. 56-60 ◽  
Author(s):  
May Win Han ◽  
Piyasiri Ekanayake ◽  
Lim Chee Ming ◽  
Voo Nyuk Yoong
Keyword(s):  
Optical Properties ◽  
Ground State ◽  
Electronic Structures ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Time Dependent ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Sensitized Solar Cells

In this study, the parameters of the photo-electrochemical properties, such as the ground state geometries, excitation energy, electronic structures, optical properties and electronics transition of lawsone were investigated by using density functional theory ( DFT ) and time dependent - DFT with B3LYP/6-31G( d) method. The solvent effect was considered in the DFT calculations and compared with the value of vacuum. From the analyses of electronic and optical properties, it is found that the lawsone satisfy the condition for good conversion efficiency as DSSCs device.

Photoexcited perylene diimide radical anions for the reduction of aryl halides: a bay-substituent effect

2018 ◽  
Vol 5 (15) ◽  
pp. 2296-2302 ◽  
Author(s):  
Hai-Xian Gong ◽  
Zhu Cao ◽  
Meng-Hua Li ◽  
Sai-Hu Liao ◽  
Mei-Jin Lin
Keyword(s):  
Excited State ◽  
Substituent Effect ◽  
Aryl Halides ◽  
Perylene Diimide ◽  
Radical Anions ◽  
State Reduction ◽  
Reduction Potentials ◽  
Photocatalytic Activities

Photoexcited perylene diimide radical anions exhibit remarkable substituent-dependent photocatalytic activities towards the reduction of aryl halides, which are mainly controlled by their excited-state reduction potentials and SOMO−1 energies.

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

Application of Atomic Layer Deposition in Dye-Sensitized Photoelectrosynthesis Cells

2021 ◽  
Vol 3 (1) ◽  
pp. 59-71
Author(s):  
Degao Wang ◽  
Qing Huang ◽  
Weiqun Shi ◽  
Wei You ◽  
Thomas J. Meyer
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Dye Sensitized ◽  
Layer Deposition
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