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Ferroelectric and Spin Crossover Behavior in a Cobalt(II) Compound Induced by Polar‐Ligand‐Substituent Motion
Author(s) -
Akiyoshi Ryohei,
Komatsumaru Yuki,
Donoshita Masaki,
Dekura Shun,
Yoshida Yukihiro,
Kitagawa Hiroshi,
Kitagawa Yasutaka,
Lindoy Leonard F.,
Hayami Shinya
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202015322
Subject(s) - fluorobenzene , chemistry , cobalt , ring (chemistry) , ligand (biochemistry) , spin crossover , substituent , crystallography , spin states , polar , stereochemistry , inorganic chemistry , organic chemistry , physics , biochemistry , receptor , benzene , astronomy
Ferroelectric spin crossover (SCO) behavior is demonstrated to occur in the cobalt(II) complex, [Co(FPh‐terpy) 2 ](BPh 4 ) 2 ⋅3ac ( 1⋅3 ac ; FPh‐terpy=4′‐((3‐fluorophenyl)ethynyl)‐2,2′:6′,2′′‐terpyridine) and is dependent on the degree of 180° flip–flop motion of the ligand's polar fluorophenyl ring. Single crystal X‐ray structures at several temperatures confirmed the flip–flop motion of fluorobenzene ring and also gave evidence for the SCO behavior with the latter behavior also confirmed by magnetic susceptibility measurements. The molecular motion of the fluorobenzene ring was also revealed using solid‐state 19 F NMR spectroscopy. Thus the SCO behavior is accompanied by the flip–flop motion of the fluorobenzene ring, leading to destabilization of the low spin cobalt(II) state; with the magnitude of rotation able to be controlled by an electric field. This first example of spin‐state conversion being dependent on the molecular motion of a ligand‐appended fluorobenzene ring in a SCO cobalt(II) compound provides new insight for the design of a new category of molecule‐based magnetoelectric materials.