Are Incorrect Bond Angles Common in Organic Chemistry?

  • Thread starter Thread starter alingy1
  • Start date Start date
  • Tags Tags
    Mistake
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 3K views
alingy1
Messages
325
Reaction score
0
Please look at picture. It seems as though the bond angles are wrong for C5H10O. Is it common in organic chemistry to not respect bond angles?
 

Attachments

  • Screen Shot 2014-06-02 at 10.40.57 PM.png
    Screen Shot 2014-06-02 at 10.40.57 PM.png
    682 bytes · Views: 532
Physics news on Phys.org
The two methyl groups pointing down on the left should consist of a dash and a wedge, giving it the bond angle of 109.5 degrees. It could be a really awful Fisher projection also :)
 
alingy1 said:
Please look at picture. It seems as though the bond angles are wrong for C5H10O. Is it common in organic chemistry to not respect bond angles?

I had to think for a moment to spot the problem - it was so obvious to me what the left part if the image is intended to mean (see ChiralWaltz post), that it required an effort to see it as 2D.

It is common in organic chemistry to draw molecules as projections, as they are (almost) never flat. Dashes and edges are used only when the molecule drawn without them is ambiguous. Here, when you know it is a projection, it doesn't matter which carbon goes up and which goes down. On top on that, these projections are almost never perfect (there is no right angle in the molecule), but are accepted as long as it is clear what is the intended spatial arrangement of the atoms.
 
Does seeing it this way make more sense?
 

Attachments

  • aldehyde.jpg
    aldehyde.jpg
    1.1 KB · Views: 492