Stability Comparison of Compounds

1. CH3-CH2-CH2
- This compound is a simple alkane with no double bonds or functional groups.
- Alkanes are considered to be relatively stable due to the presence of only single bonds between carbon atoms.
- The lack of any reactive functional groups contributes to the stability of this compound.

2. CH2=CH-CH2 (Allylic)
- This compound contains an allylic double bond, which is a type of double bond adjacent to a carbon-carbon double bond.
- Allylic compounds are generally more stable than isolated double bonds due to resonance stabilization.
- The delocalization of pi electrons into the allylic position increases stability compared to a typical alkene.

3. CH'-C-CH2
- This compound contains a carbocation, which is a positively charged carbon atom.
- Carbocations are relatively unstable due to the lack of electron density on the carbon atom.
- The positive charge makes this compound more reactive and less stable compared to compounds with no charge.

4. Ph-CH2-CH2
- This compound contains a phenyl group (Ph) attached to an alkyl chain.
- The presence of the phenyl group increases stability due to resonance effects.
- The delocalization of electrons in the phenyl group helps stabilize the compound.

Overall Comparison
- In terms of stability, the compounds can be ranked as follows:
1. CH3-CH2-CH2 (Most stable due to lack of functional groups)
2. Ph-CH2-CH2 (Stable due to phenyl group resonance)
3. CH2=CH-CH2 (Allylic stability from resonance)
4. CH'-C-CH2 (Least stable due to carbocation reactivity)