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What is chirality and how did it get in my molecules? - Michael Evans

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Improve your understanding of molecular properties with this lesson on the fascinating property of chirality. Your hands are the secret to understanding the strange similarity between two molecules that look almost exactly alike, but are not perfect mirror images.

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Chirality is an important spatial property of a single organic molecule, but organic chemists often think about the spatial relationships between two or more molecules as well. For example, we can characterize two molecules as enantiomeric if they are mirror images but not identical. Diastereomers have the same connectivity, but are not identical and are also not mirror images.
Read about enantiomorphism here and diastereomorphism here. Use the examples on these pages to both identify the stereocenters within each molecule and find instances of enantiomorphism and diastereomorphism. Think about how you might use the numbers and types of stereocenters within a particular molecule to predict how many enantiomers and diastereomers it has.

Synthesizing a chiral molecule from achiral precursors, without creating its enantiomer at the same time, happens to be a very difficult task. Many organic chemists have dedicated their careers to developing reactions that accomplish this goal. Check out the Wikipedia article on enantioselective synthesis to explore some methods chemists have used to create enantiopure, chiral compounds from achiral starting materials.

Chiral objects are not superimposable with their mirror images. An excellent example of this is your hands. Hold your hands out in front of you, with the palms facing together. Neglecting unnatural add it you can make sure ions such as jewelry, note that your hands are mirror images. Now turn your hands so that both palms face the same direction. Note that the thumbs now point in opposite directions. When the thumbs point in the same direction, the palms are opposite. Your hands are mirror images, but not superposable. Each hand is therefore chiral.

For a more detailed chemical explanation, check out this tutorial from the UCLA website.

If you think another video explanation would be helpful for you, watch this link.

One useful method for the isolation of a single enantiomer involves the separation of a mixture of enantiomers, a process called resolution. Read about resolution here, and describe in your own words how introducing a pure enantiomer of a different molecule can help separate a mixture of enantiomers.d

The Virtual Textbook of Organic Chemistry
IUPAC’s Basic Terminology of Stereochemistry.

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Meet The Creators

  • Educator Michael Evans
  • Animator Qa'ed Tung, Safwat Saleem
  • Narrator Michael Evans

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