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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: boodyx1 on January 15, 2010, 06:31:28 PM

Title: steric hindrance
Post by: boodyx1 on January 15, 2010, 06:31:28 PM

steric hindrance(in organic molecule) affect absorptivity,absorbance and intensity of (u.v-v.light) spectra.explain? (please in details) :D

Title: Re: steric hindrance
Post by: cpncoop on January 15, 2010, 07:14:43 PM

When a molecule absorbs light, it takes a bonding electron and excites it to either a non-bonding orbital.  This changes the bond length, and the molecule vibrates or emits light to return to it's ground state.  If a molecule is severely hindered (in terms of geometry or sterics), transitions can be shifted to higher energies, as the conformational changes required to achieve a stable excited state have a greater energy barrier.

Title: Re: steric hindrance
Post by: boodyx1 on January 16, 2010, 07:46:31 AM

thank you  ;D