Interplay of Redox Non-Innocence and Symmetry Breaking in a 4d Coordination Framework
Incorporating 4d and 5d metal ions into coordination frameworks offers a powerful route to quantum materials where orbital delocalization and spin-orbit coupling reshape magnetic and electronic ground states. However, such systems remain difficult to access synthetically. Here we report Mo(pyz)<sub>2</sub>I<sub>2</sub>, the first pyrazine-bridged square-lattice framework featuring a paramagnetic 4d metal center, obtained using a new organometallic precursor route that enables Mo incorporation. Structural and spectroscopic data establish a Mo<sup>III</sup>({pyz<sub>2</sub>}<sup>•-</sup>)I<sub>2</sub> formulation and reveal pronounced ligand redox non-innocence accompanied by local symmetry breaking arising from a disordered distribution of neutral and reduced pyrazine linkers─the first experimental observation of local symmetry lowering in a pyrazine-based coordination solid. Magnetic measurements show strong antiferromagnetic interactions without clear evidence of long-range order, and electrical transport indicates narrow-gap semiconducting behavior. Extending pyrazine framework chemistry to the 4d block thus requires new synthetic strategies and reveals new local structural and magnetic degrees of freedom, positioning Mo(pyz)<sub>2</sub>I<sub>2</sub> as a prototype for designing correlated and spin-orbit-entangled states in molecule-based quantum materials based on heavier transition metals.
Authors
- Z. X. Li
- Sebastian E. Reyes‐Lillo (ORCID: https://orcid.org/0000-0003-0012-9958)
- Marco Evangelisti (ORCID: https://orcid.org/0000-0002-8028-9064)
- David Gracia (ORCID: https://orcid.org/0000-0002-3511-3510)
- Andreï Rogalev (ORCID: https://orcid.org/0000-0002-0501-698X)
- Nathan J. Yutronkie (ORCID: https://orcid.org/0000-0002-8297-9376)
- Vivian Nassif (ORCID: https://orcid.org/0000-0002-2668-678X)
- Adam F. Sapnik (ORCID: https://orcid.org/0000-0001-6200-4208)
- Kasper A. Borup (ORCID: https://orcid.org/0000-0001-5013-6684)
- Luis Leyva‐Parra (ORCID: https://orcid.org/0000-0002-4210-1868)
- Diego López‐Alcalá (ORCID: https://orcid.org/0000-0001-9906-7798)
- Frédéric Aribot
- Marc Ubach Cervera (ORCID: https://orcid.org/0000-0002-3699-0195)
- Mariusz Kubus (ORCID: https://orcid.org/0000-0002-6602-2742)
- Anton Viborg (ORCID: https://orcid.org/0000-0002-1493-124X)
- Henrik M. Rønnow
- Maja A. Dunstan
- Ivica Zivkovic
- José J. Baldoví
- Bo B. Iversen
- Fabrice Wilhelm
- Kasper S. Pedersen
Institutions
- University of Copenhagen (DK)
- Centre National de la Recherche Scientifique (FR)
- Universidad Andrés Bello (CL)
- Universitat de València (ES)
- Aarhus University (DK)
- Universidad de Zaragoza (ES)
- European Synchrotron Radiation Facility (FR)
- Institut Laue-Langevin (FR)
- Instituto de Nanociencia y Materiales de Aragón (ES)
- Institut Néel (FR)
- École Polytechnique Fédérale de Lausanne (CH)
- Fundación Ciencias Exactas y Naturales (AR)
- Université Grenoble Alpes (FR)
- Technical University of Denmark (DK)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2026-02-17
- DOI
- https://doi.org/10.1021/jacs.5c19779
- Primary Topic
- Magnetism in coordination complexes
- Type
- article
- Field-Weighted Citation Impact
- 0.00