Organic chemistry concept help

In summary, the delocalization of the negative charge over the ortho and para positions of aromatic rings leads to an increase in stability for the phenoxide anion. This is due to the ability of the ortho and para positions to allow the charge to spread out, while the meta position does not have this capability. The concept of "particle in a box" is often used to explain this phenomenon. Overall, the more feasible resonance structures a molecule has, the more stable it is.
  • #1
ephemeral1
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Why does delocalization of the negative charge over the ortho and para positions of aromatic rings increase the stability of the phenoxide anion? Why do the ortho and para positions increase the stability but not the meta position? Please explain. Thank you.
 
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  • #2
Can you draw resonance forms of the phenoxide ion?
 
  • #3
You see, the ortho and para forms allow the resonance to "spread out" the charge to the O- ion at the end, while the meta position is placed just so that it cannot achieve this.
 
  • #4
Of course noting that the negative charge is more delocalized doesn't really explain why it is more stable!

Read about the "particle in a box" for an explanation. Consider a particle like an electron confined in a region of dimension L. The energy of that electron is expressed as a function of dimension L, or length, that the particle can move. If the electron is allowed to move more freely (L increases), it has a lower energy since http://en.wikipedia.org/wiki/Particle_in_a_box#cite_note-Davies5-3" The particle in a box is a one dimensional treatment but this is used as an approximation of the delocation length of an individual electron.
 
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  • #5
http://chemistry.boisestate.edu/people/richardbanks/organic/phenol.gif

Google is just lovely at times.

In general, the as the number of feasible resonance structures increases, the more stable the molecule is, for the reasons chemisttree stated.
 
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  • #6
Nice, clustro.
 

1. What is the definition of organic chemistry?

Organic chemistry is the branch of chemistry that studies the structure, properties, and reactions of carbon-containing compounds, also known as organic compounds. These compounds are found in living organisms and are essential to life on Earth.

2. What is the difference between organic and inorganic compounds?

The main difference between organic and inorganic compounds is that organic compounds contain carbon-hydrogen bonds, while inorganic compounds do not. Additionally, organic compounds are usually derived from living organisms, while inorganic compounds can be found in non-living sources such as minerals and gases.

3. How do I name organic compounds?

The naming of organic compounds follows a set of rules outlined by the International Union of Pure and Applied Chemistry (IUPAC). These rules involve identifying the longest carbon chain, determining the functional groups present, and using prefixes and suffixes to name the compound. It is important to practice and consult the IUPAC guidelines when naming organic compounds.

4. What are the types of organic reactions?

There are many types of organic reactions, but some of the most common include substitution, addition, elimination, and oxidation-reduction reactions. These reactions involve the breaking and forming of chemical bonds between carbon and other elements, resulting in the formation of new compounds.

5. How can I understand and visualize organic molecules?

One helpful way to understand and visualize organic molecules is by using molecular models. These models represent the three-dimensional structure of molecules, allowing you to see the arrangement of atoms and bonds. There are also online tools and apps available that can help visualize and manipulate organic molecules in a more interactive way.

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