Topic
Steric effects
About: Steric effects is a research topic. Over the lifetime, 16112 publications have been published within this topic receiving 319615 citations. The topic is also known as: steric hindrance.
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TL;DR: The regioselective N-alkylation of 1,2,3-triazoles 1-6 was studied, providing a general, protective, group-free method for the synthesis of N-2-substituted triazoles.
85 citations
TL;DR: On donne les constantes d'equilibre en solution benzenique pour la fixation des imidazoles, de CO, O 2 et isonitriles a deux hemes cyclophanes anthraceniques renfermant un cycle anthracene mobile piege sur l'heme as discussed by the authors.
Abstract: On donne les constantes d'equilibre en solution benzenique pour la fixation des imidazoles, de CO, O 2 et isonitriles a deux hemes cyclophanes anthraceniques renfermant un cycle anthracene mobile piege sur l'heme. Le caractere du cyclophane est tres similaire du point de vue sterique a celui des hemoproteines
85 citations
TL;DR: In this paper, the steric repulsion of the substituted methyl group results in an unusual strengthening of the hydrogen bonds, decreasing the barrier for the proton movement within the hydrogen bridge, which leads to a delocalization of the position.
Abstract: Five derivatives of an ortho-hydroxy Schiff base (2-(N-alkyl-α-iminoethyl)phenols) with very short intramolecular hydrogen bonds (dO(H)⋯N
≤ 2.500 A) were synthesised. The crystal structures were determined. The steric repulsion of the substituted methyl group results in an unusual strengthening of the hydrogen bonds, decreasing the barrier for the proton movement within the hydrogen bridge, which leads to a delocalization of the proton position. The very strong influence of the character of the substituent in the phenol ring as well as the character of the N-alkyl chain on the proton distribution is demonstrated for these hydrogen bonds from the so-called inversion range.
85 citations
TL;DR: In this article, a serie of substituted amines based ionic liquids were prepared using an aliphatic linear carboxylic acid (pentanoic acid), and the influence of structural variations on their thermodynamic properties (density, ultrasonic velocity, ionic conductivity, refractive index, viscosity and surface tension) was investigated, as a function of temperature in the range 278.15-338.15
85 citations
TL;DR: Introduction of an electron-withdrawing group on the aromatic ring of N-methylacetanilide decreased the ratio of the cis conformer, and the ratio correlates well with the Hammett sigma values of the substituents.
85 citations