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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: GradStudent4 on June 09, 2010, 10:16:02 PM

Title: Number of Valence Electrons in Phenyl Group?
Post by: GradStudent4 on June 09, 2010, 10:16:02 PM
This may be a very stupid question, but I recently read, "The number of available valence electrons from a phenyl group is 1." How is this determined? I understand how you can determine this for individual atoms, but not for a functional group. Thanks for any help.
Title: Re: Number of Valence Electrons in Phenyl Group?
Post by: Schrödinger on June 10, 2010, 02:32:28 AM
The phenyl group, I presume, is a radical. i.e, one carbon has no hydrogen attached to it, just an odd electron.

The hybridization of that Carbon atom is sp2. 2 sp2 orbitals form C-C sigma bond, and one p-orbital is used for C-C pi bond. Now the odd electron lies in the 3rd sp2 hybridized orbital, which would have overlapped with the s-orbital of Hydrogen if the molecule were benzene.

So, we have just one valence electron.
Hope this helps
Title: Re: Number of Valence Electrons in Phenyl Group?
Post by: a student on June 14, 2010, 10:15:26 AM
This may be a very stupid question, but I recently read, "The number of available valence electrons from a phenyl group is 1." How is this determined? I understand how you can determine this for individual atoms, but not for a functional group. Thanks for any help.
I would be grateful of you tell me where did you read this ? ;D I haven't heard it before  :o