A Metallic Ground State in a Niobium-Pyrazine Coordination Framework
Abstract
Conductive metal-organic frameworks (MOFs) based on low-valent heavy transition metals remain largely unexplored despite the strong metal-ligand covalency and extended orbitals that should favor electronic delocalization. Herein, we report Nb(pyz) 2 Cl 2 (pyz = pyrazine), a layered coordination framework with a metallic electronic ground state. Although charge transport in pressed pellets is limited by thermally activated grain-boundary hopping, the high room-temperature conductivity of 1.2 S cm⁻ 1 , temperature-independent Pauli susceptibility, finite Sommerfeld coefficient (g = 14.0(5) mJ K⁻ 2 mol⁻ 1 ), Wilson ratio close to unity, and periodic density functional theory calculations consistently demonstrate a finite density of states at the Fermi level. X-ray absorption spectroscopy further reveals a strongly delocalized electronic structure involving mixed Nb 4d, Cl 3p, and pyz p* states. These results identify low-valent early-4d ions as promising components for electronically delocalized coordination solids and extend metallic metal-organic frameworks beyond the 3d transition-metal series.
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BibTeX
@misc{magott2026metallic,
title = {{A Metallic Ground State in a Niobium-Pyrazine Coordination Framework}},
author = {Michał Magott and Dominik Dzierżek and Katia Dujarric and Pierre Dechambenoit and Mathieu Rouzières and Gabriela Handzlik and Leszek M. Malec and Elizaveta A. Suturina and Andrei Rogalev and Corine Mathonière and Rodolphe Clérac},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15005165/v2},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15005165/v2},
note = {CC BY},
}
RIS
TY - UNPB
TI - A Metallic Ground State in a Niobium-Pyrazine Coordination Framework
AU - Michał Magott
AU - Dominik Dzierżek
AU - Katia Dujarric
AU - Pierre Dechambenoit
AU - Mathieu Rouzières
AU - Gabriela Handzlik
AU - Leszek M. Malec
AU - Elizaveta A. Suturina
AU - Andrei Rogalev
AU - Corine Mathonière
AU - Rodolphe Clérac
PY - 2026
DA - 2026/09/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15005165/v2
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15005165/v2
AB - Conductive metal-organic frameworks (MOFs) based on low-valent heavy transition metals remain largely unexplored despite the strong metal-ligand covalency and extended orbitals that should favor electronic delocalization. Herein, we report Nb(pyz) 2 Cl 2 (pyz = pyrazine), a layered coordination framework with a metallic electronic ground state. Although charge transport in pressed pellets is limited by thermally activated grain-boundary hopping, the high room-temperature conductivity of 1.2 S cm⁻ 1 , temperature-independent Pauli susceptibility, finite Sommerfeld coefficient (g = 14.0(5) mJ K⁻ 2 mol⁻ 1 ), Wilson ratio close to unity, and periodic density functional theory calculations consistently demonstrate a finite density of states at the Fermi level. X-ray absorption spectroscopy further reveals a strongly delocalized electronic structure involving mixed Nb 4d, Cl 3p, and pyz p* states. These results identify low-valent early-4d ions as promising components for electronically delocalized coordination solids and extend metallic metal-organic frameworks beyond the 3d transition-metal series.
ER -