Steric effects and steric inhibition of resonance: structure and ionization of 2-tert-butylbenzoic acid

2001 ◽  
Vol 25 (2) ◽  
pp. 250-254 ◽  
Author(s):  
Stanislav Böhm ◽  
Otto Exner
Keyword(s):  
Steric Effects ◽  
Resonance Structure ◽  
Steric Inhibition Of Resonance

Local dipolar order induced by steric effects in smectic B phases

1982 ◽  
Vol 43 (7) ◽  
pp. 1173-1178
Author(s):  
G. Coulon
Keyword(s):  
Steric Effects ◽  
Dipolar Order

Electronic or steric effects: Detailed DFT investigations of titanium amino based Kaminsky type olefin catalysts

2018 ◽  
Author(s):  
Jörg Saßmannshausen
Keyword(s):  
Density Functional Theory ◽  
Strong Correlation ◽  
Density Functional ◽  
Steric Effects ◽  
Aryl Group ◽  
Functional Theory

We report detailed Density Functional Theory (DFT) investigations of a series of structurally similar titanium (IV) chelating σ-aryl catalysts. Particular attention was paid to the electronic charges of the Ti, C ipso of the substituted aryl group and the benzylic CH<sub>2</sub> and C<i><sub>ipso</sub></i> atoms. The Bader and NBO derived charges were compared with the recently reported polymerisation results by Chan. We found a strong correlation between the relative energies of one of the computed isomers and the activity of the catalyst. Neither NBO nor Bader charges could be convincingly correlated to the observed activity.

Estimate of Hyperconjugation Strength in Alkylaromatics and Unsaturated Hydrocarbons Derived from Refractometric Data

2020 ◽  
Vol 23 (23) ◽  
pp. 2598-2613
Author(s):  
Boris A. Zaitsev
Keyword(s):  
Quantitative Estimation ◽  
Physical Phenomenon ◽  
Unsaturated Hydrocarbons ◽  
Resonance Effects ◽  
Alkyl Derivatives ◽  
Retrospective View ◽  
Scientific Papers ◽  
Polycyclic Aromatic ◽  
Qualitative Measure ◽  
Steric Inhibition Of Resonance

: A retrospective view of exaltation of refraction observed for many unsaturated and aromatic compounds demonstrates that this physical phenomenon is undeservedly considered only as a qualitative measure of conjugation. This mini-review discusses numerous papers by the author that have been published earlier in inaccessible periodicals and collections of scientific papers. Using a great number of illustrations, the author shows that this parameter can be successfully used for quantitative estimate of resonance effects in organic and polymer chemistry. The methods for derivation of strictly additive atomic and group refraction constants are described; these constants were subsequently used as a tool that allowed quantitative estimation of resonance effects in mono-, di-, tri- and polyalkylbenzenes, alkylnaphthalenes, some alkyl derivatives of unsaturated hydrocarbons. These effects cause strictly fixed increase in refraction of carbon atoms in different structural modifications (graphene, fullerene, diamond) and in polycyclic aromatic hydrocarbons. The relevant results regarding quantitative estimation of degree of steric inhibition of resonance in sterically hindered ortho-dialkylbenzenes, 1,2,3- trialkyl-, 1,2,3,4-tetraalkyl-, and 1,2,3,4,5-polyalkylbenzenes accumulated by the author are summarized.

Configuration on the C=N double bond of monosubstituted amidines and amidoximes

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Steric Effects ◽  
Model Compounds ◽  
X Ray ◽  
Analogous Model

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).

scholarly journals Differential steric effects in the inelastic scattering of NO(X) + Ar: spin–orbit changing transitions

2019 ◽  
Vol 21 (26) ◽  
pp. 14173-14185 ◽  
Author(s):  
M. Brouard ◽  
S. D. S. Gordon ◽  
B. Nichols ◽  
V. Walpole ◽  
F. J. Aoiz ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Steric Effect ◽  
Steric Effects ◽  
Spin Orbit ◽  
First Time

The differential steric effect for spin–orbit changing collisions of NO with Ar is determined for the first time.

Steric Effects in Dissociative Adsorption of Low-Energy CH3Cl on Si(100): Orientation and Steering Effects

2008 ◽  
Vol 112 (49) ◽  
pp. 19612-19615 ◽  
Author(s):  
Michio Okada ◽  
Seishiro Goto ◽  
Toshio Kasai
Keyword(s):  
Dissociative Adsorption ◽  
Low Energy ◽  
Steric Effects

scholarly journals Coherent control of Goos-Hänchen shift in a guided-wave surface plasmon resonance structure with Rydberg atoms

2021 ◽  
Vol 3 ◽  
pp. 100065
Author(s):  
Dingyu Cai ◽  
Mengmeng Luo ◽  
Yuetao Chen ◽  
Shaoyan Gao
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Coherent Control ◽  
Rydberg Atoms ◽  
Guided Wave ◽  
Resonance Structure ◽  
Wave Surface
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