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bd40bc7c7a Mague, and R. In surface chemistry, steric effects manifest in an entropic contribution to the overall Gibbs energy. When a Lewis acid and Lewis base cannot combine due to steric hindrance, they are said to form a frustrated Lewis pair.. See also: intramolecular forces . 2007 (34): 5390. Steric inhibition of resonance is present only in benzene rings.
In pharmacology, steric effects determine how and at what rate a drug will interact with its target bio-molecules. Nature. Although steric hindrance is sometimes a problem (it prevents SN2 reactions with tertiary substrates from taking place), it can also be a very useful tool, and is often exploited by chemists to change the reactivity pattern of a molecule by stopping unwanted side-reactions (steric protection) or by leading to a preference for one stereochemical reaction course as in diastereoselectivity. PMID11385553. "A Congested in, in-Diphosphine." Organic letters, 15(9), 2179-2181. Steric effects arise from a fact that each atom within a molecule occupies a certain amount of space. "Hyperconjugation not steric repulsion leads to the staggered structure of ethane". Organometallics. Oxford: IRL Press. Steric effects often dictate reaction pathways in organic synthesis because there are fewer configurations in which molecules can collide and successfully react.