An Ytterbium-Pyrazine Square [(C <sub>5</sub> H <sub>4</sub> Me) <sub>2</sub> Yb <sup>III</sup> (pyz <sup>•–</sup> )] <sub>4</sub> Formed by Reversible Electron Transfer and Concomitant Self-Assembly
Pyrazine (pyz) has been used extensively in coordination chemistry to manifest electron delocalization in mixed-valent compounds and strongly coupled materials. In the current work, using a Yb<sup>II</sup> precursor, [(C<sub>5</sub>H<sub>4</sub>Me)<sub>2</sub>Yb<sup>II</sup>(THF)<sub>2</sub>] (<b>1</b>), a molecular square [(C<sub>5</sub>H<sub>4</sub>Me)<sub>2</sub>Yb<sup>III</sup>(pyz<sup>•-</sup>)]<sub>4</sub>·<sup>1</sup>/<sub>2</sub>(C<sub>7</sub>H<sub>5</sub>F<sub>3</sub>) (<b>2</b>) was synthesized by metal-ligand redox cooperativity. Complex <b>2</b> shows evidence of charge transfer from Yb<sup>II</sup> to pyrazine in a range of studies including structural analysis, magnetometry, vibrational spectroscopy, X-ray absorption near-edge structure spectroscopy, and electronic structure calculations. DFT calculations support the assignment of low-energy bands in the UV-vis spectrum as pyrazine-SOMO-to-metal-4f charge transfer. Magnetic studies reveal a Yb-pyz<sup>•-</sup> exchange coupling of -3.6 cm<sup>-1</sup> and pyz<sup>•-</sup>-pyz<sup>•-</sup> coupling of -18.6 cm<sup>-1</sup> for the radical bridged Yb-square complex.
Authors
- Jochen Autschbach (ORCID: https://orcid.org/0000-0001-9392-877X)
- Dumitru‐Claudiu Sergentu (ORCID: https://orcid.org/0000-0001-6570-5245)
- Stefan G. Minasian (ORCID: https://orcid.org/0000-0003-1346-7497)
- Patrick W. Smith (ORCID: https://orcid.org/0000-0001-5575-4895)
- Corwin H. Booth (ORCID: https://orcid.org/0000-0001-6827-0080)
- Brett D. Vincenzini
- Niki Mavragani (ORCID: https://orcid.org/0000-0003-0069-3233)
- Muralee Murugesu (ORCID: https://orcid.org/0000-0002-5123-374X)
- Eric J. Schelter (ORCID: https://orcid.org/0000-0002-8143-6206)
- Himanshu Gupta (ORCID: https://orcid.org/0000-0001-9843-3020)
- Asmita Sen
- Alexandra M. Bacon
Institutions
- International Civil Aviation Organization (CA)
- Alexandru Ioan Cuza University (RO)
- Lawrence Berkeley National Laboratory (US)
- University of Ottawa (CA)
- California University of Pennsylvania (US)
- National Energy Technology Laboratory (US)
- NOAA Chemical Sciences Laboratory (US)
- University at Buffalo, State University of New York (US)
Publication Details
- Journal
- Inorganic Chemistry
- Published
- 2025-07-16
- DOI
- https://doi.org/10.1021/acs.inorgchem.5c02655
- Citations
- 2
- Primary Topic
- Molecular Junctions and Nanostructures
- Type
- article
- Field-Weighted Citation Impact
- 1.46
Funders
- University of Pennsylvania
- Stavros Niarchos Foundation
- Vagelos Institute for Energy Science and Technology, University of Pennsylvania
- Chemical Sciences, Geosciences, and Biosciences Division
- Lawrence Berkeley National Laboratory