Suppression of Peierls Instability in a Metal-Halide Porous Framework.

Peierls distortion is a lattice instability in low-dimensional materials driven by electron-phonon coupling, which opens an energy gap at the Fermi level and induces a metal-insulator transition. Suppressing this distortion is crucial for stabilizing metallic and superconducting states in low-dimensional systems, yet achieving such suppression remains challenging without external chemical doping or high-pressure conditions. Metal-organic framework (MOF) forms a periodic porous structure with well-defined channels and functional sites. In this work, we harness the intrinsic periodic electrostatic potential of a porous framework to suppress the Peierls instability in one-dimensional platinum-halide (Pt-X) chains. By integrating Pt-X chains into the ordered nanochannels of the porous material, we achieved suppression of detectable Peierls distortion, as evidenced by the absence of lattice distortion and an approximately four-order-of-magnitude enhancement in its electrical conductivity (from 4.8 × 10-6 to 4.3 × 10-2 S/cm) compared to the distorted counterparts. This study demonstrates an example where the intrinsic periodic electrostatic potential of a porous framework can be employed to suppress the Peierls distortion, providing new insight for achieving controllable electronic properties in low-dimensional electronic materials.