resonance

Common Mistakes: How not to draw resonance curved arrows

January 10, 2012

No discussion of resonance structures would be complete without mention of how to royally screw them up. This isn’t something to feel bad about, by the way: there isn’t a chemist alive who hasn’t made one of these mistakes at some point. Think of it as a rite of passage. The trick is to make the mistakes [...]

Tagged as: curved arrows, mistakes, resonance

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Exploring Resonance: Pi-Donation

December 15, 2011

You’d think after five or six posts on resonance, that would be enough. But NO, friends, it just keeps going. I promise that today’s post is actually useful, although to be honest it’s probably most applicable if you’re in (or going into) org 2, since the chemistry of the functional groups discussed here  don’t really [...]

Tagged as: enamines, enols, pi donation, resonance

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Introduction to Resonance (2) : Curved Arrows!!

November 30, 2011

So last time I talked about resonance forms as being two (or more) different ways to draw the same molecule, which differ only in their distribution of electrons. Let’s look a little more closely at these resonance forms and ask, “what’s different?”, and be as specific as possible. In both cases the resonance form on the [...]

Tagged as: curved arrows, formal charge, resonance

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Introduction to Resonance

November 23, 2011

 Last time we talked about how to use electronegativity to find the electron densities in a molecule – and when to ignore formal charge. However I didn’t mention one of the factors that can sometimes complicate the analysis of electron densities: double bonds (π bonds). But let’s start with the simple stuff. In many cases, [...]

Tagged as: electron densities, formal charge, resonance

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Are these molecules conjugated?

March 8, 2011

If Org 2 has an overall theme, it’s “resonance”. Today’s post has a very simple message. Atoms with lone pairs, π bonds, radicals, and carbocations can participate in resonance: atoms that lack any of these features cannot. One way in which this comes up is in determining whether two alkenes are “conjugated” or not.  A full [...]

Tagged as: conjugation, resonance

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