The total energy, E_T; zero-point energy, thermal energies (E), enthalpies (H) and Gibbs free energies (G) were calculated for aryl substituted divalent five membered cyclic compounds Ar-C₄H₃G (G = –NH₂, –OH, –CH₃, –F, –Cl, –Br, –H, –CF₃ and –NO₂) at B3LYP/6–31+G* and B3LYP/6– 311++G** levels of theory. It could be concluded that an allenic character was constructed instead of carbenic character for both singlet and triplet states of Ar-C₄H₃G.