\(\rightarrow 10\, \pi\, {e}^{-}\)in cyclic conjugation
\(\rightarrow \text { Aromatic }\)
\((2)\) \(\rightarrow 4 \pi {e}^{-}\)in ring conjugation \(\Rightarrow\) Anti Aromatic
\((3) \Rightarrow 4 \pi {e}^{-}\)in ring conjugation \(\Rightarrow\) Anti Aromatic
\((4)\) \(\Rightarrow 6 \pi {e}^{-}\)in ring conjugation \(\Rightarrow\) Aromatic
- Cyclopentadienyl anion
$(i)$ $C{H_3} - C \equiv C - C{H_3}$
$(ii)$ $C{H_3} - C{H_2} - C{H_2} - C{H_3}$
$(iii)$ $C{H_3} - C{H_2} - C \equiv CH$
$(iv)$ $C{H_3} - CH = C{H_2}$