What is the SIR effect in organic chemistry?

Steric inhibiting resonance is abbreviated as SIR in organic chemistry .It inhibits resonance in any molecule by distorting the planar structure of the molecule which is essential requirement of a molecule to exhibit resonance . read more

The SIR effect or steric inhibition of resonance is also known as ortho effect. It is the effect specially noticed in ortho substituted aniline. When there is a steric hindrance between group at ortho position and -NH2 group, the -NH2 group rotates and it inhibits Resonance since it is not in the same plane anymore.. read more

The mesomeric effect or resonance effect is a property of substituents in a chemical compound. The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M. read more

Steric effects is critical to chemistry, biochemistry, and pharmacology. In organic chemistry, steric effects are nearly universal and affect the rates and activation energies of most chemical reactions to varying degrees. read more