Steric effects

Steric effects are nonbonding interactions that influence the shape (conformation) and reactivity of ions and molecules. Steric effects complement electronic effects, which usually dictate shape and reactivity. Steric effects result from repulsive forces between overlapping electron clouds. Steric effects are widely exploited in applied and academic chemistry.Tris(2,4-di-tert-butylphenyl)phosphite, a widely used stabilizer in polymers.Tricyclohexylphosphine, a bulky phosphine ligand used in homogeneous catalysis and, with B(C6F5)3, comprises the classic frustrated Lewis pair.2,6-Di-tert-butylphenol is used industrially as UV stabilizers and antioxidants for hydrocarbon-based products ranging from petrochemicals to plastics.Hindered amine light stabilizers are widely used in polymers.Titanium isopropoxide is a monomer, the corresponding titanium ethoxide is a tetramer. Steric effects are nonbonding interactions that influence the shape (conformation) and reactivity of ions and molecules. Steric effects complement electronic effects, which usually dictate shape and reactivity. Steric effects result from repulsive forces between overlapping electron clouds. Steric effects are widely exploited in applied and academic chemistry. Steric hindrance is a consequence of steric effects. 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 is often exploited to control selectivity, such as slowing unwanted side-reactions. Steric hindrance between adjacent groups can also affect torsional bond angles. Steric hindrance is responsible for the observed shape of rotaxanes and the low rates of racemization of 2,2'-disubstituted biphenyl and binaphthyl derivatives.