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Chemical Shifts

  1. Mar 3, 2005 #1
    Can someone please explain to me how to calculate chemical shifts only given a few constants? For example the compound is as follows:

    a benzene ring except in positions 1 and 4 there is an OCH3 group.

    given only the values of:
    alkane CH3 = 0.9
    alkane CH2 = 1.3
    alkane CH = 1.4

    O=C-CH3 --> 2.1
    -C(triple bond)C-H -->2.5
    R-CH2-X --> 3-4
    >C=C<H --> 5-6
    >C=C<CH3 --> 1.7
    Ph-H --> 7.2
    Ph-CH3 --> 2.3
    R-CHO --> 9-10
    R-COOH --> 10-12
    R-OH --> 2-5
    Ar-OH --> 4-7
    R-NH2 --> 1.5-4

    The final answer is supposed to be for the H's delta 7.2 and for the H's attached to CH3O delta 3.6. Please help I don't understand how to do any of the chemical shift calculations at all! Thank you in advance. :bugeye:
  2. jcsd
  3. Mar 4, 2005 #2


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    Science Advisor
    Gold Member

    It is somewhat complex, but we know that the compound includes phenyl H (Ph-H), and Ph-X-CH3. Therefore, the entries R-CH2X and Ph-H would be useful for you.
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