Ch

Discussion in 'Chemistry' started by astrogirl15, Nov 17, 2008.

  1. astrogirl15 Registered Member

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    10
    Is that an official name for CH?

    I know that NH3 is named Ammonia. I also know that NH3 is stable wheras CH isnt.
     
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  3. Trippy ALEA IACTA EST Staff Member

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    The answer to this question isn't quite as trivial as it might seem at first.

    -CH3 is Methyl.
    -CH2- Methylene :CH2 is Carbene.
    =CH- is Methine.

    Sometimes in a situation where four single bonds are present (as opposed to the Methine shown above with 1 double bond, and two single bonds) this is also called Methine, but I must stress that this is NOT systematic nomenclature.

    I hope that answers your question.
     
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  5. astrogirl15 Registered Member

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    Apparently only stable compounds get a name?
     
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  7. skaught The field its covered in blood Valued Senior Member

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    Uh oh.
     
  8. Trippy ALEA IACTA EST Staff Member

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    Why name something that isn't stable, and doesn't really exist?

    But as I said, it's the non-systematic name.
     
  9. Roman Banned Banned

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    11,560
    CH is too unstable to ever exist. Some unstable compounds DO get names, like Benzyne, which is benzene with a triple bond, because it exists as an intermediate, and can be detected.

    Since carbon forms the structure of organic compounds, CH in compounds does get named, albeit indirectly.

    Ethanal, for instance:

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    As you can see, there is a CH in there, but it is not "named", it is simply included in eth-, which means there are two carbons attached to each other.

    Other examples of the eth- would ethanol (CH3-CH2-OH), ethane (CH3-CH3), ethyne (CH2=CH2).

    Ethyne has only CH's in it:

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    CH's in side groups are also not given a name, like an OH group or =O, since they are counted in the length of the carbon side group.

    So a side group that looked like:
    H OH
    | |
    -C-C-C=O
    | | |
    H H OH

    The C-H bit is not named directly.

    The COOH is a carboxylic acid, and the OH is a hydroxy, but the Cs are accounted for by calling the entire chain a propane derivative. The name is actually 2-hydroxypropanoic acid.
     
  10. leopold Valued Senior Member

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    isn't this an acetylene radical?
     
  11. Trippy ALEA IACTA EST Staff Member

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    No.
    It's a trivalent functional group.
    Methine is an SP2 hybridized Carbon with one bond occupied by Hydrogen.
    An example would be Formic acid.

    Every Cabon except for 2 in this molecule is a Methine carbon (the two exceptions being where the rings join to the chain).

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    The molecule contains a 5 carbon polymethine chain.

    If I had been referring to the radical, I would have denoted as such.
     

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