A Triphenylamine with Two Phenoxy Radicals Having Unusual Bonding Patterns and a Closed-Shell Electronic State

2015 ◽  
Vol 54 (28) ◽  
pp. 8267-8270 ◽  
Author(s):  
Daisuke Sakamaki ◽  
Soichiro Yano ◽  
Toshiyuki Kobashi ◽  
Shu Seki ◽  
Takuya Kurahashi ◽  
...  
Keyword(s):  
Electronic State ◽  
Closed Shell ◽  
Phenoxy Radicals ◽  
Bonding Patterns

A Triphenylamine with Two Phenoxy Radicals Having Unusual Bonding Patterns and a Closed-Shell Electronic State

2015 ◽  
Vol 127 (28) ◽  
pp. 8385-8388 ◽  
Author(s):  
Daisuke Sakamaki ◽  
Soichiro Yano ◽  
Toshiyuki Kobashi ◽  
Shu Seki ◽  
Takuya Kurahashi ◽  
...  
Keyword(s):  
Electronic State ◽  
Closed Shell ◽  
Phenoxy Radicals ◽  
Bonding Patterns

E-Market of State Purchases in Russia

2005 ◽  
pp. 121-130 ◽  
Author(s):  
V. Ryabtsun
Keyword(s):  
Electronic State ◽  
Legal Basis ◽  
Siberian Region ◽  
Federal Target Program ◽  
Target Program

Legal basis and development of systems of electronic state purchases in Russia with special attention to the federal target program "Electronic Russia (2002-2010)" are considered in the article. The level of development of such systems is examined within the case of their functioning in the Ural-Siberian region. The results of the work of state purchases e-market in Novosibirsk and Chelyabinsk are presented.

Hydrostibination of Alkynes: A Radical Mechanism

2020 ◽  
Author(s):  
Josh MacMillan ◽  
Katherine Marczenko ◽  
Erin Johnson ◽  
Saurabh Chitnis
Keyword(s):  
Density Functional ◽  
Activation Barrier ◽  
Closed Shell ◽  
Reaction Rates ◽  
Radical Mechanism ◽  
Neutral Radical ◽  
Kinetic Isotope ◽  
Rate Limiting Step ◽  
Ionic Mechanisms ◽  
Terminal Acetylenes

The addition of Sb-H bonds to alkynes was reported recently as a new hydroelementation reaction that exclusively yields anti-Markovnikov <i>Z</i>-olefins from terminal acetylenes. We examine four possible mechanisms that are consistent with the observed stereochemical and regiochemical outcomes. A comprehensive analysis of solvent, substituent, isotope, additive, and temperature effects on hydrostibination reaction rates definitively refutes three ionic mechanisms involving closed-shell charged intermediates. Instead the data support a fourth pathway featuring neutral radical Sb<sup>II</sup> and Sb<sup>III</sup> intermediates. Density Functional Theory (DFT) calculations are consistent this model, predicting an activation barrier that is within 1 kcal mol<sup>-1</sup> of the experimental value (Eyring analysis) and a rate limiting step that is congruent with experimental kinetic isotope effect. We therefore conclude that hydrostibination of arylacetylenes is initiated by the generation of stibinyl radicals, which then participate in a cycle featuring Sb<sup>II</sup> and Sb<sup>III</sup> intermediates to yield the observed <i>Z</i>-olefins as products. This mechanistic understanding will enable rational evolution of hydrostibination as a methodology for accessing challenging products such as <i>E</i>-olefins.

Variational Method for Estimating the Dipole Moment in the Second Excited State of Fluorescein Molecule from its Electronic UV Absorption Spectra

2019 ◽  
Vol 70 (10) ◽  
pp. 3538-3544
Author(s):  
Alina Costina Luca ◽  
Ana Cezarina Morosanu ◽  
Irina Macovei ◽  
Dan Gheorghe Dimitriu ◽  
Dana Ortansa Dorohoi ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Variational Method ◽  
Electronic State ◽  
Excited Electronic State ◽  
Spectral Band ◽  
Uv Absorption ◽  
Optical Parameters ◽  
Electrical Permittivity ◽  
Fluorescein Molecule

Electro-optical parameters of fluorescein molecule in the second excited electronic state and information on the interactions with solvents were obtained from a solvatochromic study. Parameters of the solvents such as the refractive index, electrical permittivity and Kamlet-Taft parameters (hydrogen bond acidity and basicity) were related with the experimentally recorded shifts of UV absorption spectral band of fluorescein dissolved in several solvents. Through a variational method, the electric dipole moment and polarizability in excited state of fluorescein molecule were estimated. The calculus requires some parameters of the fluorescein molecule in the ground electronic state, which were determined through a quantum-mechanical study.

Redox Potential - (Electronic) Structure Relationships in 18- and 17-Electron Mononitrile (or Monocarbonyl) Diphosphine Complexes of Re and Fe

2001 ◽  
Vol 66 (1) ◽  
pp. 139-154 ◽  
Author(s):  
M. Fátima C. Guedes Da Silva ◽  
Luísa M. D. R. S. Martins ◽  
João J. R. Fraústo Da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Cyclic Voltammetry ◽  
Electronic Structure ◽  
Binding Sites ◽  
Closed Shell ◽  
Carbonyl Complexes ◽  
Metal Centre ◽  
Pt Electrode ◽  
Metal Site ◽  
Oxidation Potentials ◽  
First Time

The organonitrile or carbonyl complexes cis-[ReCl(RCN)(dppe)2] (1) (R = 4-Et2NC6H4 (1a), 4-MeOC6H4 (1b), 4-MeC6H4 (1c), C6H5 (1d), 4-FC6H4 (1e), 4-ClC6H4 (1f), 4-O2NC6H4 (1g), 4-ClC6H4CH2 (1h), t-Bu (1i); dppe = Ph2PCH2CH2PPh2), or cis-[ReCl(CO)(dppe)2] (2), as well as trans-[FeBr(RCN)(depe)2]BF4 (3) (R = 4-MeOC6H4 (3a), 4-MeC6H4 (3b), C6H5 (3c), 4-FC6H4 (3d), 4-O2NC6H4 (3e), Me (3f), Et (3g), 4-MeOC6H4CH2 (3h); depe = Et2PCH2CH2PEt2), novel trans-[FeBr(CO)(depe)2]BF4 (4) and trans-[FeBr2(depe)2] (5) undergo, as revealed by cyclic voltammetry at a Pt-electrode and in aprotic non-aqueous medium, two consecutive reversible or partly reversible one-electron oxidations assigned as ReI → ReII → ReIII or FeII → FeIII → FeIV. The corresponding values of the oxidation potentials IE1/2ox and IIE1/2ox (waves I and II, respectively) correlate with the Pickett's and Lever's electrochemical ligand and metal site parameters. This allows to estimate these parameters for the various nitrile ligands, depe and binding sites (for the first time for a FeIII/IV couple). The electrochemical ligand parameter show dependence on the "electron-richness" of the metal centre. The values of IE1/2ox for the ReI complexes provide some supporting for a curved overall relationship with the sum of Lever's electrochemical ligand parameter. The Pickett parametrization for closed-shell complexes is extended now also to 17-electron complexes, i.e. with the 15-electron ReII and FeIII centres in cis-{[ReCl(dppe)2]}+ and trans-{FeBr(depe)2}2+, respectively.

The impacts of electronic state hybridization on the binding energy of single phosphorus donor electrons in extremely downscaled silicon nanostructures

2014 ◽  
Vol 116 (6) ◽  
pp. 063705 ◽  
Author(s):  
Le The Anh ◽  
Daniel Moraru ◽  
Muruganathan Manoharan ◽  
Michiharu Tabe ◽  
Hiroshi Mizuta
Keyword(s):  
Binding Energy ◽  
Electronic State ◽  
Silicon Nanostructures
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