1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Organic element symbol R

  1. Mar 10, 2008 #1
    Organic element symbol "R"

    I keep hearing different things about what exactly the letter R represents in organic chemical structures. Does the R always represent an alkyl group or can it represent groups with heteroatoms? For example
    http://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Aldehyde2.png/60px-Aldehyde2.png
    http://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Ketone-general.png/60px-Ketone-general.png
    theres the structure of an aldehyde and a ketone. Can I safely assume that the R's attached of the ketone will be Carbon atoms and will be attached to other C or H atoms. In other words will a ketone always have alkyl groups attached to its O=C or can a ketone have any elements in it?
     
  2. jcsd
  3. Mar 10, 2008 #2
    The 'R' just means an unspecified group/molecule that's attached. You also might see 'X' to denote a halogen (fluorine, chlorine, bromine, iodine, etc.) when it's not important to specify which.

    So a aldehyde is a carbon with a double-bonded oxygen and hydrogen on it. What the 'R' stands for there could be anything, as simple as a methyl group, or some crazily complex organic molecule.

    Note that the ketone specifically notes it can have two different groups attached to it. So it might have a methyl on one side and an amino on the other side, or an ethyl and propyl, or whatever.
     
  4. Mar 12, 2008 #3
    The C of the O=C must be bound to others two C atoms, otherwise is not a ketone anylonger: if one is C and the other is H, it's an aldheide (if both are H it's Formaldehyde), if it's OH, is a carboxilic acid, etc.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Organic element symbol R
  1. Organic spectroscopy (Replies: 6)

  2. Organic reactions (Replies: 2)

  3. Organic Chemistry (Replies: 4)

  4. Organic semiconductor (Replies: 3)

Loading...