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CIS-TRANS ISOMERISM ON RING

– Example :

 

 

 

 

 

 

 

 

 

 
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Posted by on March 2, 2011 in Uncategorized

 

CIS-TRANS ISOMERISM ON C=C

–  Example : CH3CH-CHCH3

 

 

 

 

 

cis-isomer–trans-isomer-1–2-dichloroethene

 

– Diastereomers different in physical properties

 

 

 

 

 

 

 

 
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Posted by on March 2, 2011 in Uncategorized

 

HOW TO IDENTIFY CIS-TRANS ISOMER

–  Restricted rotation of carbon-carbon bonds due to:

*  C=C

*  Cyclic (ring) structure

–  Two different atoms or groups of atoms attached to each of C atom which form double bond or cyclic               structure

 

 

 

 

 

 

 
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Posted by on March 2, 2011 in Uncategorized

 

TYPE OF DIASTEREOMEDS

–  Molucules with two or more chiral centers

–  Cis-trans (geometric) isomer

* C=C (alkene)

* Disubtituted cycloalkane

 

 

 

 

 

 

 

 

 

 

 

 
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Posted by on March 2, 2011 in Uncategorized

 

OPTICALLY ACTIVITY OF ENANTIOMERS

– Two enantiomers have identical physical properties

* Melting, boiling point, and solubility

– They are differ in their behavior toward plane-polarized light

– Separate enantiomers rotate the plane of plane-polarized light equal amount but in opposite direction

– Separate enantiomers are said to optically active

 

 

 

 

 

 

 

 

 

 

 

 
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Posted by on March 2, 2011 in Uncategorized

 

Polarimeter…

  • Main part :
  1. light source
  2. Polarizer
  3. Sample tube
  4. Analyzer
  5. Scale for measuring degrees of rotation

 
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Posted by on March 1, 2011 in Uncategorized

 

OPTICAL ACTIVITY

* The ability of a chiral compound to rotate the plane-polarized light

* Compound that change (rotate) the plane o polarized light – optically active

* Compound that does not change the plane polarized light – optically inactive

 

 

 
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Posted by on February 28, 2011 in Uncategorized