Stereochemistry: Difference between revisions
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Stereochemistry refers to the three dimensional arrangement of atoms in molecules, especially those aspects that go beyond the connectivity (which atoms are connected to each other) captured in a Lewis structure. Two molecules that are mirror images of each other (enantiomers) differ in stereochemistry. Another common example are cis and trans double bonds, such as in fatty acids. | Stereochemistry refers to the three dimensional arrangement of atoms in molecules, especially those aspects that go beyond the connectivity (which atoms are connected to each other) captured in a Lewis structure. Two molecules that are mirror images of each other (enantiomers) differ in stereochemistry. Another common example are cis and trans double bonds, such as in fatty acids. | ||
== Chirality == | |||
Chiral molecules are like your hands. There are two versions, left and right, and they are mirror images (or enantiomers). The initial scenes shows how four different substituents on a tetrahedral center leads to two possible configurations. If you make a fist with your right hand and hold out your left hand flat, they are still considered mirror images because a hand is still a hand, even when you make a fist. Similarly, you sometimes have to rotate around some single bonds to have a pair of enantiomers actually look like mirror images. | |||
<table><tr><td><applet load='' name='A' size='300' frame='true' scene='82/824489/Rconfig/4'/></td><td><applet load='' name='B' size='300' frame='true' scene='82/824489/Sconfig/4'/></td></tr></table> | <table><tr><td><applet load='' name='A' size='300' frame='true' scene='82/824489/Rconfig/4'/></td><td><applet load='' name='B' size='300' frame='true' scene='82/824489/Sconfig/4'/></td></tr></table> | ||
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<text>reload initial scenes</text> | <text>reload initial scenes</text> | ||
</jmolButton></jmol> | </jmolButton></jmol> | ||
== Other forms of stereo chemistry == | |||
Clicking on the buttons below the 3D scenes shows other molecules. Each pair somehow is different in stereochemistry. For each pair, try to write a Lewis structure and a skeletal structure, and describe how they differ. | |||