Title
Bulky anion effect on the architecture of chiral dysprosium single-molecule magnets
Author
Haiet Douib, Kais Dhbaibi, Bertrand Lefeuvre, Vincent Dorcet, Thierry Guizouarn, Fabrice Pointillart
Year
2023
Journal
Chirality
Abstract
The interest for chiral tris(β-diketonato)lanthanide complexes in coordination chemistry is huge due to its Lewis acid character, optical activity, and the control of the final compound architecture. The reaction of equimolar quantities of [Dy((−)/(+)hfc)3(H2O)] (hfc− = 3-(heptafluoropropylhydroxymethylene)-(+/−)-camphorate) and L led to the formation of a pair of enantiomers for dinuclear complexes [Dy((−)/(+)hfc)3(L)]2⋅C7H16 ([(−)/(+)1]⋅C7H16) (L = 4′-(4′′′-pyridyl-N-oxide)-1,2′:6′1′′-bis-(pyrazolyl)pyridine]). Starting from the previous experimental protocol with the addition of bulky BArF anions, a partial dissociation of the chiral [Dy((−)/(+)hfc)3(H2O)] was observed leading to the isolation of a mono-dimensional cationic chiral polymer {[Dy((−)/(+)hfc)2(L)][BarF]}n⋅nCH3NO2 ([(−)/(+)2]n⋅nCH3NO2). Natural circular dichroism (NCD) highlighted an exciton CD couplet for [(−)/(+)2]n but not for (−)/(+)1. The latter behaves as a single-molecule magnet (SMM) with a blocking temperature up to 4 K, whereas [(−)/(+)2]n is a 1D assembly of field-induced SMMs with a magnetic relaxation occurring through a Raman process only.
Instrument
J-815, V-650
Keywords
Bulky anion, architecture, chiral dysprosium, single-molecule magnets