CHEM 150 Lecture Notes - Lecture 18: Chemical Formula, Structural Formula, Dextrorotation And Levorotation
Document Summary
Isomers: di erent compounds that have the same chemical formula. 2 types: geometrical isomers & optical isomers. Cis/trans (more stable and easier to synthesize) Identical bonds with di erent orientation of the bonds in space. Cannot be interconverted without breaking chemical bonds. Cis: 2 particular atoms are adjacent to each other. Cis isomer & mirror image are not superimposable = optical. Trans: 2 particular atoms are on opposites sides in the structural formula. Trans isomer & mirror image are superimposable. Cis & trans isomers have di erent chemical and physical properties. Non-superimposable mirror images superimposable: if one structure is laid over the other, the positions of all the atoms will match (left & right hand look identical but cannot put left glove on right hand) Di er in their interactions with plane-polarized light. Chiral: molecules with non superimposable mirror images. Most chemical & all physical properties (except the direction of rotation of plane-polarized light) of enantiomers are identical.
