Cationic cyclocodimerization. 4. Syntheses and structures of [3.3]metacyclophane derivatives. Cyclization controlled by an orbital interaction and a steric constraint

1987 ◽  
Vol 52 (8) ◽  
pp. 1409-1413 ◽  
Author(s):  
Jun Nishimura ◽  
Akihiro Ohbayashi ◽  
Yuzuru Horiuchi ◽  
Yukihiro Okada ◽  
Shunichi Yamanaka ◽  
...  
Keyword(s):  
Orbital Interaction ◽  
Steric Constraint

Nucleophilicity and its parametrization

1989 ◽  
Vol 54 (1) ◽  
pp. 117-135
Author(s):  
Oldřich Pytela ◽  
Vítězslav Zima
Keyword(s):  
Regression Analysis ◽  
Linear Correlation ◽  
Correlation Equation ◽  
Chemical Processes ◽  
General Tendency ◽  
Orbital Interaction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Two Parameter ◽  
Better Than

The method of conjugate deviations based on the regression analysis has been suggested for construction of a new nucleophilicity scale. This method has been applied to a set of 28 nucleophiles participating in 47 physical and chemical processes described in literature. The two-parameter nucleophilicity scale obtained represents-in the parameter denoted as ND-the general tendency to form a bond to an electrophile predominantly on the basis of the orbital interaction and-in the parameter denoted as PD-the ability to interact with a centre similar to the proton (basicity). The linear correlation equation involving the ND, PD parameters and the charge appears to be distinctly better than the most significant relations used. The correlation dependences have the physico-chemical meaning. From the position of individual nucleophiles in the space of the ND and PD parameters, some general conclusions have been derived about the factors governing the reactivity of nucleophiles.

Niobocene Dichloride and Niobocene Diiodide: Electronic Absorption Spectra and Electron Spin Resonance

1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Point Group ◽  
Esr Spectra ◽  
Ligand Field ◽  
Orbital Interaction ◽  
Symmetry Point Group ◽  
Spin Orbital ◽  
Halide Ligands

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.

Effects of steric constraint on chromium(III) complexes of tetraazamacrocycles, 4: Comparison of the trans-difluoro-complexes of tet a, 1,4-C2-cyclam, and 1,11-C3-cyclam

2007 ◽  
Vol 360 (5) ◽  
pp. 1482-1492 ◽  
Author(s):  
Michael T. Vagnini ◽  
W. Caleb Rutledge ◽  
Chuanjiang Hu ◽  
Donald G. VanDerveer ◽  
Paul S. Wagenknecht
Keyword(s):  
Steric Constraint

scholarly journals Spin-sate reconfiguration induced by alternating magnetic field for efficient oxygen evolution reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Zhou ◽  
Peifang Wang ◽  
Hao Li ◽  
Bin Hu ◽  
Yan Sun ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Reaction Pathway ◽  
Low Cost ◽  
Orbital Interaction ◽  
New Paradigm ◽  
Metal Organic ◽  
Energy Conversion Devices

AbstractOxygen evolution reaction (OER) plays a determining role in electrochemical energy conversion devices, but challenges remain due to the lack of effective low-cost electrocatalysts and insufficient understanding about sluggish reaction kinetics. Distinguish from complex nano-structuring, this work focuses on the spin-related charge transfer and orbital interaction between catalysts and intermediates to accelerate catalytic reaction kinetics. Herein, we propose a simple magnetic-stimulation approach to rearrange spin electron occupation in noble-metal-free metal-organic frameworks (MOFs) with a feature of thermal-differentiated superlattice, in which the localized magnetic heating in periodic spatial distribution makes the spin flip occur at particular active sites, demonstrating a spin-dependent reaction pathway. As a result, the spin-rearranged Co0.8Mn0.2 MOF displays mass activities of 3514.7 A gmetal−1 with an overpotential of ~0.27 V, which is 21.1 times that of pristine MOF. Our findings provide a new paradigm for designing spin electrocatalysis and steering reaction kinetics.

scholarly journals Observation of an Orbital Interaction-Induced Feshbach Resonance inYb173

2015 ◽  
Vol 115 (26) ◽  
Author(s):  
M. Höfer ◽  
L. Riegger ◽  
F. Scazza ◽  
C. Hofrichter ◽  
D. R. Fernandes ◽  
...  
Keyword(s):  
Feshbach Resonance ◽  
Orbital Interaction

Effects of Steric Constraint on Chromium(III) Complexes of Tetraazamacrocycles, 2. Comparison of the Chemistry and Photobehavior of thetrans-Dichloro- andtrans-Dicyano- Complexes of Cyclam, 1,4-C2-Cyclam, and 1,11-C3-Cyclam†

2005 ◽  
Vol 44 (25) ◽  
pp. 9518-9526 ◽  
Author(s):  
Paul S. Wagenknecht ◽  
Chuanjiang Hu ◽  
Denise Ferguson ◽  
Lawrence C. Nathan ◽  
Robert D. Hancock ◽  
...  
Keyword(s):  
Steric Constraint

Effect of conjugation pathway on electronic structures in p-π* conjugated polymers with fused borepin units

2021 ◽  
Author(s):  
Yohei Adachi ◽  
Fuka Arai ◽  
Mitsuru Sakabe ◽  
Joji Ohshita
Keyword(s):  
Conjugated Polymers ◽  
Electronic Structures ◽  
Orbital Interaction ◽  
Conjugated Materials

Among conjugated materials, the p-π* conjugated polymers have attracted much attention due to their unique electronic structures derived from the orbital interaction between the empty p-orbital on boron and the...

scholarly journals The Surface Properties of Calcite: An Adsorption Model with Orbital Control

2001 ◽  
Vol 19 (3) ◽  
pp. 237-244 ◽  
Author(s):  
Nikolai V. Nikolenko
Keyword(s):  
Surface Properties ◽  
Organic Compounds ◽  
Electron Donor ◽  
Organic Molecules ◽  
Orbital Interaction ◽  
Adsorption Model ◽  
Acceptor Interaction ◽  
Donor Acceptor ◽  
Correlation Parameters ◽  
Adsorptive Properties

The energies of unoccupied and occupied orbitals were used as the correlation parameters between the electronic and adsorptive properties of organic molecules. A model describing the chemisorption of organic compounds on CaCO3 involving two types of interaction, i.e. two-electron, donor–acceptor interaction HOMO(adsorbent) → LUMO(adsorbate) and four-electron, three-orbital interaction HOMO(adsorbent) → {LUMO(adsorbate) + HOMO(adsorbate)}, was proposed. It was concluded that strengthening of the bond involved in chemisorption occurred if the energies of the occupied orbitals associated with the adsorbate and adsorbent were concurrent.

scholarly journals Gate-Voltage-Modulated Spin Precession in Graphene/WS2 Field-Effect Transistors

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2879
Author(s):  
Amir Muhammad Afzal ◽  
Muhammad Farooq Khan ◽  
Jonghwa Eom
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Spin Precession ◽  
Orbital Interaction ◽  
Transition Metal Dichalcogenide ◽  
Precession Angle ◽  
Spin Orbital ◽  
Spintronic Devices ◽  
Non Local ◽  
Spin Fet

Transition metal dichalcogenide materials are studied to investigate unexplored research avenues, such as spin transport behavior in 2-dimensional materials due to their strong spin-orbital interaction (SOI) and the proximity effect in van der Waals (vdW) heterostructures. Interfacial interactions between bilayer graphene (BLG) and multilayer tungsten disulfide (ML-WS2) give rise to fascinating properties for the realization of advanced spintronic devices. In this study, a BLG/ML-WS2 vdW heterostructure spin field-effect transistor (FET) was fabricated to demonstrate the gate modulation of Rashba-type SOI and spin precession angle. The gate modulation of Rashba-type SOI and spin precession has been confirmed using the Hanle measurement. The change in spin precession angle agrees well with the local and non-local signals of the BLG/ML-WS2 spin FET. The operation of a spin FET in the absence of a magnetic field at room temperature is successfully demonstrated.

Sign in / Sign up

Export Citation Format

Share Document