Topology as a Design Variable for Multiproperty Engineering in Synthesized 4–5–6–8 Carbon Nanoribbons

Resumo

Nonbenzenoid carbon frameworks expand the design landscape of low-dimensional materials by introducing controlled departures from hexagonal symmetry. Here, we demonstrate that the experimentally realized 4–5–6–8 carbon nanoribbon establishes a topology-driven paradigm for multiproperty engineering rather than representing a simple structural variant of graphene nanoribbons. Combining hybrid density functional theory, parametrized tight-binding, and molecular dynamics within a coherent multiscale framework, we show that the symmetry-broken lattice stabilizes a hierarchy of bonds while remaining in the same energy range with ribbons of comparable width. This geometric organization produces a robust semiconducting state with a hybrid-functional electronic band gap exceeding 1 eV and enables strain to function as a controllable parameter for electronic modulation. Notably, a tight-binding Hamiltonian fitted only at equilibrium, accurately captures the strain-dependent electronic band evolution, indicating that the essential physics is dominated by the topology itself. Mechanical analysis reveals high stiffness with fracture governed by the largest polygonal motifs, demonstrating that geometric asymmetry redistributes stress without compromising structural integrity. In addition, intrinsic phonon scattering suppresses lattice thermal conductance, allowing favorable thermoelectric performance to emerge without extrinsic disorder. The optical response further confirms that nonequivalent ring connectivity reorganizes interband transitions, promoting strong absorption within the visible range and efficient photocarrier generation. These results position the topology as a governing physical parameter capable of coupling elasticity, electronic structure, thermal transport, and optical activity, establishing the 4–5–6–8 nanoribbon as a unified platform for the predictive design of multifunctional carbon materials.

ACS Materials Au, 2026 · Fator de impacto 9,1.

DOI 10.1021/acsmaterialsau.6c00131