Ppt 7 isomers


Published on

Published in: Technology, Business
1 Comment
No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Ppt 7 isomers

  1. 1. Isomers Structural, Geometric, Enantiomer SBI4U
  2. 2. Isomers <ul><li>Isomers are compounds that have the same molecular formula but different structures and therefore different chemical properties. </li></ul>All three molecules chemical formula is C 6 H 12 O 6 You need to memorize these three molecules
  3. 3. Structural Isomer <ul><li>same KIND and AMOUNT of atoms (molecular formula) but the atoms have different connectivity </li></ul><ul><ul><li>For example, butane and isobutane have the same molecular formula C4H10, but butane has a straight skeleton and isobutane has a branched skeleton. </li></ul></ul>
  4. 4. Structural isomers usually have different physical and chemical properties
  5. 5. Structural Isomer <ul><li>How many different structures can you make from C 5 H 12 ? </li></ul><ul><li>How many structural isomers of C 20 H 42 </li></ul>
  6. 6. Isomers of pentane
  7. 7. Structural Isomers <ul><li>C 5 H 12 3 </li></ul><ul><li>C 20 H 42 366,319 </li></ul><ul><li>Structural isomers may also differ in the location of double bonds. </li></ul>
  8. 8. Geometric Isomers <ul><li>same molecular formula and the SAME connectivity but different spatial arrangements </li></ul><ul><li>Different arrangement around a carbon. </li></ul><ul><li>Due to inflexibility of double bonds </li></ul><ul><li>Cis (same side) and trans formatio n (across) </li></ul>
  9. 10. Which are geometric isomers and which are structural isomers?
  10. 11. Enantiomer <ul><li>molecules that are mirror images of each other </li></ul><ul><li>Note : left and right hands are a pair of enantiomers (mirror images not identical ) </li></ul><ul><li>non-superimposable mirror image </li></ul><ul><li>Name other body parts that are enantiomers </li></ul>
  11. 12. Enantiomer <ul><li>Requirement: an asymmetric carbon (has 4 different groups bonded to it) </li></ul><ul><li>Chiral molecule: molecules with an asymmetric carbon such that it has a non-superimposable mirror image </li></ul><ul><li>Achiral: a molecule that lacks chiral properties </li></ul><ul><li>A molecule that can exist as a pair of enantiomers has the property of chirality </li></ul>
  12. 13. Away from you Towards you
  13. 14. Is this a structural, geometric or enantiomer isomer?
  14. 15. Enzymes, which themselves are always chiral, often distinguish between the two enantiomers of a chiral substrate . Chiral objects (glove) have different interactions with the two enantiomers of other chiral objects (left and right hand). Analogy: A left hand will not fit into a right-handed glove
  15. 16. <ul><li>Even the subtle structural differences in two enantiomers have important functional significance because of emergent properties from the specific arrangements of atoms. </li></ul><ul><ul><li>One enantiomer of the drug thalidomide reduced morning sickness, its desired effect, but the other isomer caused severe birth defects (teratogenic). </li></ul></ul><ul><ul><li>administering only one enantiomer will not prevent the teratogenic effect in humans. </li></ul></ul><ul><ul><li>The body naturally creates the enantiomer. </li></ul></ul>
  16. 17. Things to keep in mind… <ul><li>http://2.bp.blogspot.com/_K91FA3B4cpM/SJ_NUmBWWGI/AAAAAAAAACY/UzL8H8Q4oag/s400/ist2_1744503_frustration.jpg </li></ul><ul><li>Are the molecules identical? If they are, they are not isomers. </li></ul><ul><li>Always look for structural isomers first (look at C’s) </li></ul>
  17. 18. Birth Defects
  18. 19. other Enantiomers <ul><li>Other biological processes may be triggered by only one of the two possible enantiomers of a chiral molecule, often being unresponsive to the other enantiomer. For example, S-carvone (&quot;left-handed&quot;) is the flavor of caraway, while R-carvone (&quot;right-handed&quot;) is the flavor of spearmint. </li></ul>
  19. 20. Videoclips <ul><li>http://www.youtube.com/watch?v=MnD-nxtRouc </li></ul><ul><li>http://www.youtube.com/watch?v=rT48OFFaDwE&feature=related </li></ul>