Work

Reduction of Hexaazatrinaphthylenes by Masked Divalent Lanthanide Dinitrogen Reagents

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide The oxidation state +2 is of interest in rare-earth chemistry since it allows these conventionally redox-inactive metals to be used as reducing agents. However, the divalent oxidation state is difficult to form for most rare-earth elements, and the ensuing compounds are often unstable. Here, we describe an approach to rare-earth reduction chemistry that circumvents the divalent oxidation state by using compounds of trivalent rare earths that store reducing electrons on the dinitrogen ligand [N 2 ] 2–, akin to “masked” divalent reactivity. Thus, the dinitrogen complexes [ ( Cp 2 ttt M ) 2 ( μ ‐1, 2‐N 2 ) ] ( 1 M, M = Y, Gd, Tb, Dy, Cp ttt = 1,2,4-C 5 t Bu 3 H 2 ) reduce hexaazatrinaphthylene and its hexamethyl derivative to give trimetallic [ ( Cp 2 ttt M ) 3 ( R 6 HAN ) ], where the [R 6 HAN] 3– ligands (R = H, 2 M; R = Me, 3 M ) form with S = 1/2, and with elimination of N 2 . The structures of 2 M and 3 M reveal that the tert -butyl substituents strongly influence the core geometry of these trimetallic complexes. Analysis of the magnetism and electronic structure of 2 Gd and 3 Gd identifies ferromagnetic metal-radical exchange, with coupling constants of J = +2.87 cm –1 and +3.07 cm –1, respectively (−2 J formalism). The unusual ferromagnetic exchange is a consequence of charge transfer to the gadolinium 5d, 6s, and 6p orbitals from the radical ligands.

Source: Inorganic Chemistry

Authors: Arpan Mondal, Christopher G. T. Price, Alexander Steiner, Jinkui Tang, Richard A. Layfield

Institutions: University of Sussex, University of Liverpool, Chinese Academy of Sciences, Changchun Institute of Applied Chemistry, State Key Laboratory of Rare Earth Resources Utilization

Language: English

Topic: Organometallic Complex Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: University of Sussex, National Natural Science Foundation of China, Engineering and Physical Sciences Research Council

Awards: Isolobal Solutions to the Hysteresis Challenge in Single-Molecule Magnetism, A Single-Crystal X-ray Diffractometer for High-Power, High-Throughput Chemical Crystallography, Metal-organic frameworks as platforms for air-stable organometallic single-molecule magnets, Lanthanides and Actinides in the +1 Oxidation State, G8297966677