657 views

### Where do the lone pairs go in the “true” resonance structure?

Consider the "true" resonance structure of $\ce{CO3^2-}$: The bottom diagram leaves out the 2 lone pairs, so 4 electrons disappeared in the bottom image as compared to the top one. Are these ...
587 views

### VSEPR theory, chemical bond and quantum mechanics

VSEPR theory correctly predicts the shapes of many symmetry-broken molecules such as $\ce{H2O}$ and $\ce{NH3}$. Take $\ce{NH3}$ for example. In VSEPR theory, the nitrogen atom is (approximately) at ...
337 views

### What is the correct way to verify a structure's geometry, for example for benzene?

My goal is to compare a calculated bond length with experimental data. Benzene is obviously common enough to expect sufficient experimental data to be available for it on the internet. I have found ...
220 views

### If I can't draw resonance structures for a pi system, does that mean it doesn't exist?

Whilst trying to answer this question I came across an interesting situation regarding the relationship between resonance structures and molecular orbitals. There are two places that you can ...
125 views

### Can a molecule be achiral whilst it's resonance form chiral?

I'm trying to work out whether methylphenylsulfoxide is a chiral molecule. It is my understanding that the sulfur uses sp2 hybridised orbitals. Why is this? The central sulfur atom is bound to 3 ...
177 views

### Generalizations regarding functional groups on benzene ring

While studying several organic mechanisms (high school level), I came to an interesting generalization. I claim that negative charge on phenoxide ion first ALWAYS delocalises onto the ring and then ...
66 views

### Why does coumarin predominantly exist in keto form?

By applying the logic that phenol exists in enol form rather than keto form as it attains aromatic character, why is it not the case in coumarin?
182 views

### Which is most stable resonance structure of 4-nitrophenoxide ion?

According to my coaching module the first structure is more stable. Why is this so? I feel both must be approximately equally stable since negative charge is on oxygen in both cases. Would someone ...
120 views

### Resonance structure and stability

Does the existence of resonance structures always translate as stability? I've been taught that resonance structures generally "spread out" charge in order to compensate for deficiency or excess of ...
106 views

### Mechanism of Biosynthesis of Terpenes

There is a specific part of the biosynthesis of terpenes that makes me confused: According to this mechanism, the double bond of the isopentenyl pyrophosphate attacks the primary carbocation, when it ...