Rank the following radicals in order of decreasing stability

**Question**



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> Rank the following radicals in order of decreasing stability
>  ![enter image description here](https://i.stack.imgur.com/5hnhz.jpg)![enter image description here](https://i.stack.imgur.com/RFFOV.jpg)![enter image description here](https://i.stack.imgur.com/lMnEU.jpg)![enter image description here](https://i.stack.imgur.com/A7H6g.jpg) 
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Aromaticity makes a cyclic compund more stable. Here, 1 and 3 are aromatic since they follow Huckels rule(Or am I wrong here?). So, I thought maybe 3 is most stable followed by 1, then followed by 2 and 4(I dont know which is more stable out of 2 and 4). But, that's not the case. 3 is most stable, but the next stable one is 2 and not 1. I don't get how. 





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> Here, 1 and 3 are aromatic since they follow Huckels rule(Or am I wrong here? 
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Yes you're wrong over here, for applying the Huckel's rule the compound must be a closed circuit of delocalized electrons. In both the cases the circuits are not closed 




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If you're not aware of [Conjugation](https://en.m.wikipedia.org/wiki/Conjugated_system) then give that a read .  

Now 
The most stable compound is 3 since the extent of conjugation is the greatest i.e 2 pi bonds. 


3 is more stable than 4. Even though 4 is aromatic it is an **aryl** free radical the p orbital containing the radical is out of the plane and can't be stabilized through resonance/Hyperconjugation.  

In fact I would say that option 4 is the least stable compound . 


The second most stable compound is is 2 since it is stabilized via resonance which is more effective than Hyperconjugation; 1 is stabilized by Hyperconjugation. 


**3 is more stable than 2** since the extent of conjugation is greater.


The order of stability will be  

$$\mathrm{3 > 2 > 1 > 4}$$ 


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