Conjugated planar polymers and tubular nanobelts of the perfect in-plane [55555] metallo-annulene Pt©C15H10.

CONTEXT: Using the newly reported perfect in-plane [55555] metallo-annulene D5h Pt©C15H10 (1) (Zhao et al., Eur. J. Inorg. Chem. 2025, 28, e202500420) as building blocks via partial dehydrogenations and based on extensive density functional theory calculations, we predict herein their stable conjugated planar polymers (Pt©C15)nH6n+4 (n = 2-9) (2-9) and (Pt©C15H6)10 (10), non-metal sandwich complexes C2(Pt©C15H10)2 (1'), [C2(Pt©C15)2]nH2(6n+4) (n = 2-9) (2'-9'), and [C2(Pt©C15H6)2]10 (10'), and tubular nanobelts (Pt©C15H6CH2)n (n = 8, 10, 12) (11, 12, 13). Detailed adaptive natural density partitioning (AdNDP) analyses indicate that the [55555] metallo-annulene polymers (Pt©C15)nH6n+4 (2-9) and (Pt©C15H6)10 (10) consist of conjugated π-aromatic Pt©C15 building blocks interconnected by C6 hexagonal units, non-metal bis([55555] metallo-annulene) sandwich complexes [C2(Pt©C15)2]nH2(6n+4) (2'-9') and [C2(Pt©C15H6)2]10 (10') contain n -C≡C- non-metal coordination centers each sandwiched between two aromatic Pt©C15 ligands, while the tubular [55555] metallo-annulene nanobelts (Pt©C15H6CH2)n (11, 12, 13) possess n conjugated π-aromatic Pt©C15 building blocks interlinked by n > CH2 carbene bridges. Bowl-shaped C5v M©C40H15 (M = Au, Ag, Cu) (14) and their metal sandwich complexes D5h Cr5(M©C40H15)2 (14') are also proposed. The IR, Raman, and UV-vis spectra of the concerned species are theoretically simulated to facilitate their experimental characterizations. METHOD: All metallo-annulene structures were fully optimized at the B3LYP level using Gaussian 09, with SDD pseudopotentials/basis sets for the metals and 6-31G* basis set for C and H. Frequency analysis indicated that all structures as true minima. UV-Vis spectra were simulated via TD-DFT at B3LYP/def2-TZVP with the SMD solvent model (dichloromethane). BOMD simulations were performed using CP2K (GTH-PBE pseudopotentials, DZVP-MOLOPT-GTH basis sets), AdNDP bonding analyses were conducted and VMD and CYLview were used for structure and molecular orbital visualization.