Double-Decker Ferrocene Analogue Derived from Flexible 14π Triphyrin(2.1.1) along with an Unusual Diels–Alder Adduct: Synthesis, Characterization, and Mechanistic Studies

14π-Triphyrin(2.1.1) is used to synthesize a double-decker sandwich complex like ferrocene. The presence of only two meso-CF3 substituents provides the macrocycle with enough flexibility to undergo bowl-shaped deformation in order to complex with Fe(II) ions, forming a low-spin diamagnetic complex. Further, the Cp ligand of the metal carrier [{Fe(CO)2(Cp)}2] forms a Diels–Alder adduct with the triphyrin macrocycle at higher temperatures, which does not undergo complexation. The plausible role of factors behind the formation of sandwich complexes in [14]triphyrin(2.1.1) was explored using first-principles molecular dynamics.