3 research outputs found
Probing bistability in FeII and CoII complexes with an unsymmetrically substituted quinonoid ligand
The generation of molecular platforms, the properties of which can be
influenced by a variety of external perturbations, is an important goal in the
field of functional molecular materials. We present here the synthesis of a
new quinonoid ligand platform containing an [O,O,O,N] donor set. The ligand is
derived from a chloranilic acid core by using the [NR] (nitrogen atom with a
substituent R) for [O] isoelectronic substitution. Mononuclear FeII and CoII
complexes have been synthesized with this new ligand. Results obtained from
single crystal X-ray crystallography, NMR spectroscopy,
(spectro)electrochemistry, SQUID magnetometry, multi-frequency EPR
spectroscopy and FIR spectroscopy are used to elucidate the electronic and
geometric structures of the complexes. Furthermore, we show here that the spin
state of the FeII complex can be influenced by temperature, pressure and light
and the CoII complex displays redox-induced spin-state switching. Bistability
is observed in the solid-state as well as in solution for the FeII complex.
The new ligand presented here, owing to the [NR] group present in it, will
likely have more adaptability while investigating switching phenomena compared
to its [O,O,O,O] analogues. Thus, such classes of ligands as well as the
results obtained on the reversible changes in physical properties of the metal
complexes are likely to contribute to the generation of multifunctional
molecular materials
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