Reduction Potentials and Electronic Structures of Phenyl-Substituted Borazines

1964 ◽  
Vol 86 (23) ◽  
pp. 5153-5160 ◽  
Author(s):  
D. F. Shriver ◽  
Donald E. Smith ◽  
Pauline. Smith
Keyword(s):  
Electronic Structures ◽  
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.

The Nature of Oxide Surfaces: Topographic and Electronic Structure

1993 ◽  
Vol 51 ◽  
pp. 966-967
Author(s):  
Dawn A. Bonnell ◽  
Yong Liang
Keyword(s):  
Transition Metal Oxides ◽  
Electronic Structures ◽  
Recent Progress ◽  
Spatial Localization ◽  
Level Of Detail ◽  
Scanning Tunneling ◽  
Oxide Surfaces ◽  
Tunneling Microscopy ◽  
Considerable Effort ◽  
Complete Understanding

Recent progress in the application of scanning tunneling microscopy (STM) and tunneling spectroscopy (STS) to oxide surfaces has allowed issues of image formation mechanism and spatial resolution limitations to be addressed. As the STM analyses of oxide surfaces continues, it is becoming clear that the geometric and electronic structures of these surfaces are intrinsically complex. Since STM requires conductivity, the oxides in question are transition metal oxides that accommodate aliovalent dopants or nonstoichiometry to produce mobile carriers. To date, considerable effort has been directed toward probing the structures and reactivities of ZnO polar and nonpolar surfaces, TiO2 (110) and (001) surfaces and the SrTiO3 (001) surface, with a view towards integrating these results with the vast amount of previous surface analysis (LEED and photoemission) to build a more complete understanding of these surfaces. However, the spatial localization of the STM/STS provides a level of detail that leads to conclusions somewhat different from those made earlier.

Cobaloxime-Based Double Complex Salts as Efficient and Versatile Catalysts for the Light-Driven Hydrogen Evolution Reaction

2020 ◽  
Author(s):  
Elisabeth Hofmeister ◽  
Jisoo Woo ◽  
Tobias Ullrich ◽  
Lydia Petermann ◽  
Kevin Hanus ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Systematic Study ◽  
Cobalt Complexes ◽  
Spectroscopic Studies ◽  
Double Complex ◽  
Double Complex Salts ◽  
Noble Metal Catalysts ◽  
Reduction Potentials ◽  
Complex Salts

Cobaloximes and their BF<sub>2</sub>-bridged analogues have emerged as promising non-noble metal catalysts for the photocatalytic hydrogen evolution reaction (HER). Herein we report the serendipitous discovery that double complex salts such as [Co(dmgh)<sub>2</sub>py<sub>2</sub>]<sup>+</sup>[Co(dmgBPh<sub>2</sub>)<sub>2</sub>Cl<sub>2</sub>]<sup>-</sup> can be obtained in good yields by treatment of commercially available [Co(dmgh)<sub>2</sub>pyCl] with triarylboranes. A systematic study on the use of such double complex salts and their single salts with simple counterions as photocatalysts revealed HER activities comparable or superior to existing cobaloxime catalysts and suggests ample opportunities for this compound class in catalyst/photosensitizer dyads and immobilized architectures. Preliminary electrochemical and spectroscopic studies indicate that one key advantage of these charged cobalt complexes is that the reduction potentials as well as the electrostatic interaction with charged photosensitizers can be tuned.

Phosphoryl- and Phosphonium-Bridged Viologens as Stable Two- and Three-Electron Acceptors for Organic Electrodes

2020 ◽  
Author(s):  
Colin R. Bridges ◽  
Andryj M. Borys ◽  
Vanessa Béland ◽  
Joshua R. Gaffen ◽  
Thomas Baumgartner
Keyword(s):  
Molecular Weight ◽  
Organic Molecules ◽  
Electrode Materials ◽  
High Energy ◽  
Electron Acceptors ◽  
Low Molecular Weight ◽  
Reduction Potentials ◽  
Organic Electrode ◽  
High Reduction ◽  
High Specific Energy

Low molecular weight organic molecules that can accept multiple electrons at high<br>reduction potentials are sought after as electrode materials for high-energy sustainable batteries. To date their synthesis has been difficult, and organic scaffolds for electron donors significantly outnumber electron acceptors. Herein, we report two highly electron deficient phosphaviologen derivatives from a phosphorus-bridged 4,4-bipyridine and characterize their electrochemical properties. Phosphaviologen sulfide (PVS) and P-methyl phosphaviologen (PVM) accept two and three electrons at high reduction potentials, respectively. PVM can reversibly accept 3 electrons between 3-3.6 V vs. Li/Li+ with an equivalent molecular weight of 102 g/(mol e-) (262 mAh/g), making it a promising scaffold for sustainable organic electrode materials having high specific energy densities.

Advanced Electronic Structures

1992 ◽  
Author(s):  
Mark van Schilfgaarde
Keyword(s):  
Electronic Structures
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