CH3•Is Planar Due to H−H Steric Repulsion. Theoretical Study of MH3•and MH3Cl (M = C, Si, Ge, Sn)

1996 ◽  
Vol 15 (5) ◽  
pp. 1477-1487 ◽  
Author(s):  
F. Matthias Bickelhaupt ◽  
Tom Ziegler ◽  
Paul von Ragué Schleyer
Keyword(s):  
Theoretical Study ◽  
Steric Repulsion

Theoretical study of substituent effects. Analysis of steric repulsion by means of paired interacting orbitals

1989 ◽  
Vol 54 (11) ◽  
pp. 2568-2573 ◽  
Author(s):  
Hiroshi Fujimoto ◽  
Yoshitaka Mizutani ◽  
Jun Endo ◽  
Yasuhisa Jinbu
Keyword(s):  
Theoretical Study ◽  
Substituent Effects ◽  
Steric Repulsion

Theoretical study on the torsional potential of alkyl, donor, and acceptor substituted bithiophene: the hidden role of noncovalent interaction and backbone conjugation

2015 ◽  
Vol 17 (6) ◽  
pp. 4127-4136 ◽  
Author(s):  
Tzu-Jen Lin ◽  
Shiang-Tai Lin
Keyword(s):  
Theoretical Study ◽  
Noncovalent Interactions ◽  
Noncovalent Interaction ◽  
Steric Repulsion ◽  
Torsional Potential ◽  
Donor And Acceptor

The torsional potential of substituted bithiophene is influenced not only by steric repulsion, but also by backbone conjugation and noncovalent interactions.

scholarly journals Theoretical Study of N-Heterocyclic-Carbene–ZnX2 (X = H, Me, Et) Complexes

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6147
Author(s):  
Mirosław Jabłoński
Keyword(s):  
Theoretical Study ◽  
Twist Angle ◽  
Steric Effects ◽  
Torsional Angle ◽  
Steric Repulsion ◽  
Hydrogen Atoms ◽  
Wide Range ◽  
The Relationship ◽  
Tetrel Bonds ◽  
Negligible Influence

This article discusses the properties of as many as 30 carbene–ZnX2 (X = H, Me, Et) complexes featuring a zinc bond C⋯Zn. The group of carbenes is represented by imidazol-2-ylidene and its nine derivatives (labeled as IR), in which both hydrogen atoms of N-H bonds have been substituted by R groups with various spatial hindrances, from the smallest Me, iPr, tBu through Ph, Tol, and Xyl to the bulkiest Mes, Dipp, and Ad. The main goal is to study the relationship between type and size of R and X and both the strength of C⋯Zn and the torsional angle of the ZnX2 plane with respect to the plane of the imidazol-2-ylidene ring. Despite the considerable diversity of R and X, the range of dC⋯Zn is quite narrow: 2.12–2.20 Å. On the contrary, D0 is characterized by a fairly wide range of 18.5–27.4 kcal/mol. For the smallest carbenes, the ZnX2 molecule is either in the plane of the carbene or is only slightly twisted with respect to it. The twist angle becomes larger and more varied with the bulkier R. However, the value of this angle is not easy to predict because it results not only from the presence of steric effects but also from the possible presence of various interatomic interactions, such as dihydrogen bonds, tetrel bonds, agostic bonds, and hydrogen bonds. It has been shown that at least some of these interactions may have a non-negligible influence on the structure of the IR–ZnX2 complex. This fact should be taken into account in addition to the commonly discussed R⋯X steric repulsion.

The effect of steric repulsion on the torsional potential of n-butane: a theoretical study

Tetrahedron ◽  
2015 ◽  
Vol 71 (32) ◽  
pp. 5119-5123 ◽  
Author(s):  
Milovan Stojanović ◽  
Jovana Aleksić ◽  
Marija Baranac-Stojanović
Keyword(s):  
Theoretical Study ◽  
Steric Repulsion ◽  
Torsional Potential

scholarly journals Sterically Facilitated Intramolecular Nucleophilic NMe2 Group Substitution in the Synthesis of Fused Isoxazoles: Theoretical Study

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5977
Author(s):  
Alexander S. Antonov ◽  
Elena Yu Tupikina ◽  
Valerii V. Karpov ◽  
Valeriia V. Mulloyarova ◽  
Victor G. Bardakov
Keyword(s):  
Nucleophilic Substitution ◽  
Theoretical Study ◽  
Model Reaction ◽  
Steric Repulsion ◽  
Reaction Intermediates ◽  
Intramolecular Nucleophilic Substitution ◽  
Gibbs Energies ◽  
Naphthalene Series

The influence of steric repulsion between the NMe2 group and a second ortho-(peri-)substituent in the series of 1-dimethylaminonaphthalene and N,N-dimethylanilene ortho-oximes on the ease of the NMe2 group’s intramolecular nucleophilic substitution is studied. Possible reaction intermediates for three mechanisms are calculated (ωB97xd/def-2-TZVP), and their free Gibbs energies are compared to model reaction profiles. Supporting experiments have proved the absence of studied reactivity in the case of simple 2-dimethylaminobenzaldoxime, which allowed us to establish reactivity limits. The significant facilitation of NMe2 group displacement in the presence of bulky substituents is demonstrated. The possibility of fused isoxazoles synthesis via the intramolecular nucleophilic substitution of a protonated NMe2 group in the aniline and naphthalene series is predicted.

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