Polymorphism in a Cobalt-Based Single-Ion Magnet Tuning Its Barrier to Magnetization Relaxation.
A large barrier to magnetization reversal, a signature of a good single-molecule magnet (SMM), strongly depends on the structural environment of a paramagnetic metal ion. In a crystalline state, where SMM properties are usually measured, this environment is influenced by crystal packing, which may be different for the same chemical compound, as in polymorphs. Here we show that polymorphism can dramatically change the magnetic behavior of an SMM even with a very rigid coordination geometry. For a cobalt(II) clathrochelate, it results in an increase of the effective barrier from 109 to 180 cm-1, the latter value being the largest one reported to date for cobalt-based SMMs. Our finding thus highlights the importance of identifying possible polymorphic phases in search of new, even more efficient SMMs.
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Alexander A
AA
Pavlov
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Yulia V
YV
Nelyubina
Kyiv National Taras Shevchenko University , 01601 Kyiv, Ukraine.
Svitlana V
SV
Kats
Kyiv National Taras Shevchenko University , 01601 Kyiv, Ukraine.
Larysa V
LV
Penkova
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences , 119991 Moscow, Russia.
Nikolay N
NN
Efimov
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Artem O
AO
Dmitrienko
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Anna V
AV
Vologzhanina
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Alexander S
AS
Belov
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Yan Z
YZ
Voloshin
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 119991 Moscow, Russia.
Valentin V
VV
Novikov