avenlea

7+ Year Member
Mar 29, 2011
498
615
Status (Visible)
  1. Pre-Medical
Hi,

I got a passage recently that had an alkene and a carbene and asked which was the electrophile and nucleophile. I was very confused by why the alkene would be considered to be the nucleophile and have more electron density when the carbene literally has a lone pair on it.

Also confused why pi electrons and pi orbitals contribute to nucleophilicity in general.

Thanks!
 

tdod

7+ Year Member
Oct 30, 2011
253
30
Status (Visible)
  1. Medical Student
Hi,

I got a passage recently that had an alkene and a carbene and asked which was the electrophile and nucleophile. I was very confused by why the alkene would be considered to be the nucleophile and have more electron density when the carbene literally has a lone pair on it.

Also confused why pi electrons and pi orbitals contribute to nucleophilicity in general.

Thanks!

π orbitals contribute to nucleophilicty b/c the π orbitals are located above and below the plane of the sigma bond. Because the sigma bond is directly between two nuclei, the π bond is above and below the 2 nuclei (see google images). Consequently, the π electrons are less stabilized by the nuclei and therefore more nucleophilic.

The carbene is electrophilic because it has an incomplete octet; in contrast, an alkene carbon has a complete octet.
 
  • Like
Reactions: 1 user
This thread is more than 6 years old.

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.
About the Ads