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Title: A linear cobalt(II) complex with maximal orbital angular momentum from a non-Aufbau ground state
Orbital angular momentum is a prerequisite for magnetic anisotropy, although in transition metal complexes it is typically quenched by the ligand field. By reducing the basicity of the carbon donor atoms in a pair of alkyl ligands, we synthesized a cobalt(II) dialkyl complex, Co(C(SiMe 2 ONaph) 3 ) 2 (where Me is methyl and Naph is a naphthyl group), wherein the ligand field is sufficiently weak that interelectron repulsion and spin-orbit coupling play a dominant role in determining the electronic ground state. Assignment of a non-Aufbau (d x 2 –y 2 , d xy ) 3 (d xz , d yz ) 3 (d z 2 ) 1 electron configuration is supported by dc magnetic susceptibility data, experimental charge density maps, and ab initio calculations. Variable-field far-infrared spectroscopy and ac magnetic susceptibility measurements further reveal slow magnetic relaxation via a 450–wave number magnetic excited state.
Authors:
; ; ; ; ; ; ; ; ;
Award ID(s):
1800252
Publication Date:
NSF-PAR ID:
10226199
Journal Name:
Science
Volume:
362
Issue:
6421
Page Range or eLocation-ID:
eaat7319
ISSN:
0036-8075
Sponsoring Org:
National Science Foundation
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