Draw all the linear acyclic constitutional isomers that have the molecular formula C6H6 and contain only single and triple bond(s).

Answer 1

Hi Affar B.,

OK, but why do you need help on this? You could just sit and draw them, after analyzing the pattern required!

The six carbons must be linearly connected, by (at least) single bonds.

If you start adding triple bonds in instead of single bonds, you rapidly find out that you can only have how many triple bonds? Call this value "N".

Now that you know that number, you can figure out where to put those triple bonds. If you start numbering carbons from one end, the first triple bond could logically go right after the first carbon, joining it to the 2nd carbon. Call that position 1. If you have a triple bond there, you can't set another onto position 2 -- why? So the next place a triple bond COULD then go is position 3. And so on.

There's really a limited number of ways that the N bonds can be placed! But, make sure that you don't inadvertently include a way that you already have listed, if you turned the molecule around end-for-end!

If you end up with more than 4 ways, you've done something wrong.

-- Cheer, --Mr. d.