A Conductive Heterometallic Coordination Polymer Hosting a Quasi-1D S = 1/2 Antiferromagnetic Chain

Conductive coordination polymers (CPs) offer a chemically tunable platform for exploring correlated electronic states. However, integrating a well-defined quantum spin chain into such conductive systems remains a fundamental challenge, as the electronic delocalization needed for conductivity often disrupts low-dimensional spin topology. Here, we demonstrate that the heterometallic framework Ag₄CuBHT (BHT = benzenehexathiol) concurrently hosts a nearly ideal S = 1/2 antiferromagnetic spin chain and exhibits high electrical conductivity. Crystalline films of Ag₄CuBHT exhibit a conductivity of 17 S cm^-1 at 300 K, with its intrinsic metallic nature confirmed by ultraviolet photoelectron spectroscopy and band-structure calculations. Magnetic susceptibility measurements on Ag₄CuBHT reveal a broad maximum, characteristic of spin-1/2 antiferromagnetic chain behavior. Analysis using the Bonner-Fisher model yields a strong intrachain exchange coupling of J/k_B = 294 K. The absence of long-range magnetic order, along with weak interchain interactions, establishes Ag₄CuBHT as a nearly ideal quasi-1D antiferromagnet. First-principles calculations uncover an orbital-selective mechanism enabling the coexistence of itinerant electrons and localized spins. This work identifies Ag₄CuBHT as a pioneering conductive CP hosting a quasi-1D quantum spin-lattice, opening new avenues for the concurrent design of spin topology and electronic transport in molecular quantum materials.