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Particle in a box polyene

  1. Feb 18, 2012 #1
    hello there,

    i've read in several places the following: if you have a polyene with J double bonds, and taking into account that the average C-C lenght is aprox 140 pm, then the lenght of the box is:


    And I don't get why 2??? the number of bonds is not 2J, but 2J-1, for cases such as hexatriene"!!!!


    thanks :)
  2. jcsd
  3. Feb 18, 2012 #2
  4. Feb 18, 2012 #3
    thanks, but there it just tells you to do number of carbons times lenght of bond. which makes sense. I want to be able to related the lenght of the box to the number of double bonds in the polyene
  5. Feb 18, 2012 #4
    Hi. The lines between fomula (4) and (5) may be the answer to your question. Square of number of bonds are corresponding to energy. Regards.
    Last edited: Feb 18, 2012
  6. Feb 18, 2012 #5
    uhhhm thanks but i don't really see what that has to do with the lenght..........
  7. Feb 26, 2012 #6
    Hi. http://phys-chem.com/pdf/CPL.pdf gives you more detailed explanation. All the pai electrons freely move along the axis of the molecule from one end to the other. They occupy states from the lowest i.e. zero node to higher ones i.e. 1,2 ,3 nodes. Regards.
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