What is meant by steric hindrance in chemistry?

Steric hindrance at a given atom in a molecule is the congestion caused by the physical presence of the surrounding ligands, which may slow down or prevent reactions at the atom. In 1, the carbonyl carbon is bonded to two hydrogen atoms. In 2, it is bonded to a hydrogen atom and a methyl group.

What is the meaning of steric factors?

Also called the probability factor, the steric factor is defined as the ratio between the experimental value of the rate constant and the one predicted by collision theory. It can also be defined as the ratio between the pre-exponential factor and the collision frequency, and it is most often less than unity.

Does steric hindrance affect E2?

E2 elimination will dominate with most nucleophiles (even if they are weak bases). No SN2 substitution due to steric hindrance.

How is steric hindrance measured?

Steric hindrance is indeed a generic term for a quantifiable phenomenon: electron-electron repulsion, or (much) more broadly, chemical physics. Electron-electron repulsion can be measured simply/crudely by Coulomb’s law: E=q1q24πϵ0r,F=q1q24πϵ0r2.

What is hindrance effect?

Steric hindrance is the slowing of chemical reactions due to steric bulk. It is usually manifested in intermolecular reactions, whereas discussion of steric effects often focus on intramolecular interactions. Steric hindrance between adjacent groups can also affect torsional bond angles.

What does tert butoxide do?

tert-butoxide can be used to form the “less substituted” alkenes in elimination reactions (the E2, specifically). Most of the time, elimination reactions favor the “more substituted” alkene – that is, the Zaitsev product.

What is steric strain in organic chemistry?

Steric strain (van der Waals strain): An increase in molecular potential energy (strain) caused when atoms or groups separated by at least four covalent bonds are forced closer than their van der Waals radii allow.