Geometric aspects of ions and molecules affecting their shape and reactivity
The parent cyclobutadiene (R = H) readily dimerizes but the R = tert-butyl derivative is robust.[1]
Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is generally a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape (conformation) and reactivity of ions and molecules. Steric effects complement electronic effects, which dictate the shape and reactivity of molecules. Steric repulsive forces between overlapping electron clouds result in structured groupings of molecules stabilized by the way that opposites attract and like charges repel.
^Günther Maier; Stephan Pfriem; Ulrich Schäfer; Rudolf Matusch (1978). "Tetra-tert-butyltetrahedrane". Angew. Chem. Int. Ed. Engl. 17 (7): 520–1. doi:10.1002/anie.197805201.
Stericeffects arise from the spatial arrangement of atoms. When atoms come close together there is generally a rise in the energy of the molecule. Steric...
substituent, δ is the sensitivity factor for the reaction to stericeffects, and Es is the steric substituent constant. Polar substituent constants describe...
considered stericeffects. Basic bonding and stericeffects are at times insufficient to explain many structures, properties, and reactivity. Thus, steric effects...
reaction. EDGs are therefore often known as activating groups, though stericeffects can interfere with the reaction. An electron withdrawing group (EWG)...
that stericeffects also affect the relative reaction rates, however, for demonstration of principle for solvent polarity on SN2 reaction rates, steric effects...
properties of the compound. This is caused by stericeffects and bonding interactions along with polar effects caused by the various substituents which are...
alkenes is disfavored by steric hindrance between the cobalt centre and the secondary alkyl ligand. Bulky ligands exacerbate this steric hindrance. Hence, the...
2-orbital-4-electron (steric) repulsions are dominant over hyperconjugation. A valence bond theory study also emphasizes the importance of stericeffects. Naming alkanes...
form adducts which exhibit stericeffects. For example: trimethyltin chloride, when reacting with diethyl ether, exhibits steric repulsion between the methyl...
Molecules that are more sterically hindered require arrangements that are more linear, and thus react more slowly. Stericeffects play a significant role...
In coordination chemistry, the ligand cone angle (θ) is a measure of the steric bulk of a ligand in a transition metal coordination complex. It is defined...
note that stereoelectronic effects should not be misunderstood as a simple combination of stericeffects and electronic effects. Founded on a few general...
(180°). There are both steric and electronic effects that affect the relative stability of conformers. Ordinarily, stericeffects predominate to place large...
to the functional groups present in the reactants and their inherent stericeffects. In more straightforward polymerizations, alkenes form polymers through...
electron-withdrawing group if at the meta position. At the ortho position, stericeffects are likely to cause a significant alteration in the Hammett equation...
A sterimol parameter is a set of vectors which describes the steric occupancy of a molecule. First developed by Verloop in the 1970s. Sterimol parameters...
equilibrium is easily reversed and dynamic. The equilibrium is sensitive to stericeffects. Arguably, the most common hemiacetals are sugars, for example glucose...
1995). "Substrate specificity of small-intestinal lactase: study of the stericeffects and hydrogen bonds involved in enzyme-substrate interaction". Carbohydrate...
the mesomeric effect. Such effects are also described as electron-rich and electron withdrawing. Additional stericeffects result from the volume occupied...
severely limit the reaction rate. Since this reaction occurs in one step, stericeffects drive the reaction speed. In the intermediate step, the nucleophile...
chelating atoms in the ligand by changing the structure, or by using stericeffects to force a conformational change in the ligand that bends the molecule...
2-orbital-4-electron (steric) repulsions are dominant over hyperconjugation. A valence bond theory study also emphasizes the importance of stericeffects. Conjugated...
intersection of this exciplex state with the ground state in a balance of stericeffects, electrostatic interactions, stacking interactions, and relative conformations...
larger steric effect than methyl. This difference in stericeffects can be used to help predict reactivity in chemical reactions. Stericeffects play a...
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