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    Attached i have the h1 nmr spectra of styrene (CH2=CH-C6H5) please can someone classify the peaks according to where they came from in the molecule?
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    Any ideas yourself?
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    (Original post by EierVonSatan)
    Any ideas yourself?
    i think maybe the ch is the doublet as it sees ch2 but what i don't get is why there is a quartet as i cannot see anywhere in the structure where a proton can see 3 hydrogens
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    look at the structure. The phenyl protons are pretty obvious, which only leaves 3 left to assign. Think about the coupling constants, there are 3 double doublets.

    Remember how double bonds effect coupling.
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    (Original post by bluenicey)
    i think maybe the ch is the doublet as it sees ch2 but what i don't get is why there is a quartet as i cannot see anywhere in the structure where a proton can see 3 hydrogens
    Is this for A-level? The rules you learn at A-level won't let you explain the splittings here :nah:
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    (Original post by EierVonSatan)
    Is this for A-level? The rules you learn at A-level won't let you explain the splittings here :nah:
    true, you've either got a ******* of a teacher or this is extension work.

    I did stuff like this in uni Chem.
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    (Original post by EierVonSatan)
    Is this for A-level? The rules you learn at A-level won't let you explain the splittings here :nah:
    Although you are expected to understand geometric isomerism, so it's not a huge leap to see the non-equivalent environments in an alkene for NMR.
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    (Original post by charco)
    Although you are expected to understand geometric isomerism, so it's not a huge leap to see the non-equivalent environments in an alkene for NMR.
    When you only know the n+1 rule it might be, to be honest, especially when you need to start talking about the magnitude of J and some more complicated splittings such as double doublets and such

    Happy to go through it, but just wanted to make sure the OP knows that it's not really A-level material (if they're doing A-level/equivalent).
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    (Original post by EierVonSatan)
    When you only know the n+1 rule it might be, to be honest, especially when you need to start talking about the magnitude of J and some more complicated splittings such as double doublets and such

    Happy to go through it, but just wanted to make sure the OP knows that it's not really A-level material (if they're doing A-level/equivalent).
    Agreed, the degree of sophistication is beyond A' level, but an A' level student should be able to recognise that the protons are in different environments and likely to produce a more complex splitting pattern.
 
 
 
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