IIT JEE , AIEEE Forum - Chemistry , Organic Chemistry - criterion for optical activity of isomers????

shub

criterion for optical activity of isomers????even if mirror images are non superimposable...can they still be optically inactive???

santosh05

it may happen...if dre r more dan 1 chiral c den it may or may nt b optically actve..........

santosh05

u also hav 2 c odr conditions lyk plane of symmetry,,,centrer of symmetry

akshansh

The primary condition for optical activity is that some enantiomer/mirror image must be in excess to the other. Otherwise there will be cancellation of effects of each isomer.

waterdemon

1)Optical Isomerism:

Compounds having Similar Physical and Chemical properties but
differing in the behaviour toward polarised light are called as
"Optical Isomers" and This phenomenon is called as "Optical-
Isomerism"

For A compound to be Optically active it must be:
(a)Chiral
(b)non-Super imposable on its mirror image

The molecules which are not superimposable on their mirror
images are called as "Chiral Molecules"

Eg:

(a)     CH₃               (b)        CH₃
   l                              l
   H - C - OH                HO - C - H
     l                              l
     CH₂CH₃                       CH₂CH₃

Here above (a) and (b) are mirror images of each other.
And it is clear that (a) 2-Butanol is "non-superimposable"

Non-Super Imposable mirror images are also called as
"Enantiomers"

Hope it helps you.

Cheers !!! @@ !!!

eistien

hey but non superimposability is the essential criterian no for optical activity and santosh05 as u say if there are more than one chiral compund the compound becomes opitcally inactive only when it is superimposable

non superimposable mirror images of chiral carbon molecule is always optically active!!!

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