Inspired by the newly discovered in-plane [55555] metallo-annulene frameworks in 3D [Os]C15H10 ([Os] = OsL1 L2 and L represents PPh3, CO, or PEt3 σ-ligands in axial direction) and recently proposed perfect 2D in-plane [55555] metallo-annulene complexes D5h MC15H10 (M = Pt, Pd, Ni), based on extensive first-principles theory calculations, we predict herein a series of perfect in plane [5555] metallo-annulene frameworks in 3D D4h [Fe]C12H8 (1, [Fe] = Fe(CO)2) and D4h [Co]C12H8+ (2, [Co] = Co(CO)2) and perfect 2D in-plane [5555] nonmetallo-annulene complexes including D4h PC12H8– (3), D4h SC12H8 (4), and D4h ClC12H8+ (5). Detailed bonding pattern and ring current analyses indicate that planar tetracoordinate metal or nonmetal centers participate in the delocalized π-bonding systems of the annulene complexes, rendering π-aromaticity and extra stability to the systems. Such species with a planar [12]C12H8 annulene ligand can be enlarged in 2D to form the C4v [Fe]C36H16 (6), D4h [Co]C36H16+ (7), D4h PC36H16– (8), D4h SC36H16 (9), and Cs ClC36H16+ (10) and expanded in 3D to generate the tubular nanobelt C2v (SC12H4)12 (11) via partial dehydrogenations. The NMR, IR, and UV-vis spectra of the most concerned species 1–5 are computationally simulated to facilitate their future experimental characterizations.
