Steric Repulsion
Steric Repulsion - Related Videos
01:10
Radical Reactivity: Steric Effects
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2023
The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified. Along with electronic factors, steric factors also account...
03:45
Assessing Attractive or Repulsive Activity of Proteins Using Hippocampal Neurons
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2025
This video demonstrates a method to assess protein activity using hippocampal neurons over patterned protein zones. Neurons exhibit repulsion in test protein zones and attachment in control protein zones, highlighting the effects of attractive or repulsive protein activity.
01:18
Directing and Steric Effects in Disubstituted Benzene Derivatives
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2023
When disubstituted benzenes undergo electrophilic substitution, the product distribution depends on the directing effect of both substituents. When the directing effects of both substituents reinforce each other, a single product is obtained. For example, bromination of p-nitrotoluene occurs ortho to the methyl group and meta to the nitro group, which is the same position, resulting in a single product. However, if the directing effects of the two groups oppose each other, the more strongly...
08:11
Stripe Assay to Study the Attractive or Repulsive Activity of a Protein Substrate Using Dissociated Hippocampal Neurons
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Cited by 7 •
2016
Axon guidance molecules regulate neuronal migration and targeted growth-cone navigation. We present a powerful method, the stripe assay, to assess the ability of guidance molecules to attract or repulse neurons. In this protocol, we demonstrate the stripe assay by showing FLRT2's ability to repel cultured hippocampal neurons.
04:01
VSEPR Theory and the Effect of Lone Pairs
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2020
Effect of Lone Pairs of Electrons on Molecule Geometry It is important to note that electron-pair geometry around a central atom is not the same thing as its molecular structure. Molecular structure describes the location of the atoms, not the electrons. The geometry that includes all electron pairs is the electron-pair geometry. The electron-pair geometries describe all regions where electrons are located, bonds as well as lone pairs. The structure that includes only the placement of the...
FAQs
At very short separations, the energy penalty from steric repulsion arises because electron density is forced into the same region. The resulting energy increase makes arrangements with greater separation more favorable, so it can shift a molecule’s preferred conformation rather than merely alter its appearance. This energy difference provides a basis for comparing alternative structures and identifying the more stable arrangement.
Steric repulsion becomes more significant when atoms or molecular groups approach closely and their electron clouds overlap. Larger or bulkier groups can therefore make particular conformations less favorable when the structure places them near one another. Molecular changes that increase separation can reduce this energetic disadvantage, influencing bond angles, preferred conformations, and the relative stability of isomers.
Molecular structures can adopt arrangements that keep crowded groups apart, because this reduces the energy associated with overlapping electron clouds. The same principle helps explain why different isomers may not have equal stability: their groups can occupy different spatial relationships. Comparing these arrangements connects three observable structural features, conformation, bond angle, and isomer stability, through their differing steric environments.
A useful structural assessment identifies bulky groups, examines how closely they approach one another, and compares alternative arrangements or isomers. The arrangement that keeps groups more separated is generally favored when steric effects dominate. This comparison helps chemists anticipate changes in molecular conformation, recognize crowded regions, and determine whether a reactive site may be difficult to access.
In substitution reactions, the spatial arrangement around a reactive site can determine how easily another species reaches it. Steric repulsion from nearby groups may block that access, making a crowded pathway less favorable and redirecting the reaction toward an alternative pathway. Examining the groups surrounding the site therefore helps connect molecular structure with reaction accessibility and pathway selection.
Steric repulsion can favor one spatial arrangement over another when competing molecular orientations place groups at different distances. In stereoselective chemistry, that preference can influence which isomer or arrangement forms. During ligand binding, crowded regions may hinder access or favor a particular fit. These effects make spatial organization important when interpreting molecular recognition and crowded chemical systems.