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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.  more » « less
Award ID(s):
1800252
PAR ID:
10226199
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Science
Volume:
362
Issue:
6421
ISSN:
0036-8075
Page Range / eLocation ID:
eaat7319
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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