Double-DeckerFerrocene Analogue Derived from Flexible14π Triphyrin(2.1.1) along with an Unusual Diels–AlderAdduct: 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.