4f/5d Hybridization Induced Single-Electron Delocalization in an Azide-Bridged Dicerium Complex

Abstract

Dilanthanide complexes with one-electron delocalization are important targets for understanding the specific 4f/5dbonding feature in lanthanide chemistry. Here, we report an isolable azide-bridged dicerium complex 3 [{(Trapen TMS )Ce} 2 (μ-N 3 )] • [Trapen = tris (2-aminobenzyl)amine; TMS = SiMe 3 ], which is synthesized by the reaction of tripodal ligand-supported (Trapen TMS )-Ce IV Cl complex 2 with NaN 3 . The structure and bonding nature of 3 are fully characterized by X-ray crystal diffraction analysis, electron paramagnetic resonance (EPR), magnetic measurement, cyclic voltammetry, X-ray absorption spectroscopy, and quantum-theoretical studies. Complex 3 presents a trans-bent central Ce−N 3 −Ce unit with a single electron of two mixed-valent Ce atoms. The unique lowtemperature (2 K) anisotropic EPR signals [g = 1.135, 2.003, and 3.034] of 3 indicate that its spin density is distributed on the central Ce−N 3 −Ce unit with marked electron delocalization. Quantum chemical analyses show strong 4f/5d orbital mixing in the singly occupied molecular orbital of 3, which allows for the unpaired electron to extend throughout the cerium-azide-cerium unit via a multicentered one-electron (Ce−N 3 −Ce) interaction. This work extends the family of mixed-valent dilanthanide complexes and provides a paradigm for understanding the bonding motif of ligandbridged dilanthanide complexes.

Modulating the Magnetic Dynamics of Five‐Coordinate DyIII Single‐Molecule Magnets by the Substitution Effect on the Axial Ligand

“…Moreover, some related studies have shown that tripod ligands have advantages in the construction of fivecoordinate triangular bipyramidal complexes. [27][28][29][30][31][32] Inspired by previous work, we were interested in preparing a new class of five-coordinate triangular bipyramid mononuclear Dy III -based SIMs with local D 3h symmetry. For deeper understanding of magneto-structural correlation and detailed theoretical elucidations of the dynamic magnetic behaviors in five-coordinate Dy III SIMs.…”