What would the IUPAC name of the molecule:
H2C=C=CH2 be?
is 1,2-propene right?
It has two double bonds and should be named a diene. I would name it 1,2-propadiene. But note that the double bonds can't be arranged any other way; therefore, I don't know if the 1,2 is necessary or not. Propadiene may be sufficient but I'm not up enough on IUPAC rules for organic nomenclature to know.
Here's a link but that doesn't prove anything unless it specifically says it's IUPAC approved. I have a call in to a friend of mine who is an organic chemist but I've not heard from him.
http://en.wikipedia.org/wiki/Propadiene
http://en.wikipedia.org/wiki/Propadiene
My friend called and said he thinks propadiene is sufficient.
Thanks!
Yes, you are correct. The IUPAC name for the molecule H2C=C=CH2 is 1,2-propene.
To arrive at this answer, you need to follow the IUPAC rules for naming alkenes:
1. Identify the longest continuous carbon chain that contains the double bond. In this case, there are three carbons in a row, so the parent chain is propane.
2. Number the carbon atoms in the parent chain so that the double bond receives the lowest possible number. Since the double bond is between the first and second carbon atoms, you number from the side closest to the double bond. In this case, the numbering starts from the left.
3. Indicate the position of the double bond by giving the number of the first carbon atom involved in the double bond. In this case, it is between the first and second carbon, so it is 1.
4. Add the suffix "-ene" to indicate that it is an alkene. Therefore, the complete name is 1,2-propene.
By following these steps, you can determine the correct IUPAC name for various organic compounds.