Synthesis, Structure, and Property of Tris(biphenyldiyl)yttrium(III) Tris(binaphthyldiyl)yttrium(III) and Tris(binaphthyldiyl)erbium(III) Complexes

TL;DR

Scientists synthesized new rare-earth metal complexes with unique bidentate ligands and studied their structures and magnetic properties.

Contribution

The paper reports the first homoleptic rare-earth metal complexes with identical bidentate σ-hydrocarbyl ligands.

Findings

Tris(biphenyldiyl)yttrium(III) and similar complexes were synthesized and structurally characterized.

Complex 3 shows slow magnetic relaxation typical of single-molecule magnets.

Magnetic relaxation in complex 3 is primarily through a Raman process.

Abstract

In the recent development of homoleptic σ-hydrocarbyl
rare-earth
metal complexes focusing on reactivity and catalytic activity, rare-earth
metal complexes with a variety of alkyl ligands have been synthesized,
and the principle for designing thermally stable σ-hydrocarbyl
rare-earth metal complexes has been established. Nevertheless, there
has been no report of homoleptic rare-earth metal complexes comprising
only identical bidentate σ-hydrocarbyl ligands. Herein, we present
homoleptic σ-hydrocarbyl rare-earth metal complexes possessing
bidentate biaryldiyl ligands, tris­(biphenyl-2,2′-diyl)­yttrium­(III)
complex 1, tris­(1,1′-binaphthyl-2,2′-diyl)­yttrium­(III)
complex 2, and tris­(1,1′-binaphthyl-2,2′-diyl)­erbium­(III)
complex 3. Single-crystal X-ray crystallography revealed
the trigonal prismatic geometry of 1, along with the
trigonal antiprismatic geometry of 2 and 3, each constructed through three-centered two-electron bonds among
the rare-earth metal, ipso-carbon, and lithium. The
static and dynamic magnetic properties of 3 were investigated
in the solid state, showing a slow magnetic relaxation typical of
single-molecule magnets. The fitting of the magnetic behavior of 3 and the ab initio theoretical calculations
indicated that the magnetic relaxation of 3 occurs primarily
through a Raman relaxation process.

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