Abstract:
Halide-bridged polymers have gained significant interest due to their diverse properties and potential
applications. Stacked Cu2L2X4 dimers, where L is an organic ligand and X can be Cl or Br , are of
interest because a chloride analogue where L = 2-pyridone, had previously been reported to exhibit
bulk ferromagnetism, which augured great potentiality for this class of compounds. The synthesis,
structural characterization, magnetic susceptibility measurements, and computational studies of two
isostructural CuClMI (MI = methylisothiazolinone) and CuBrMI polymers of Cu(II), along with a related
CuClPYR (PYR = 2-pyridone) is reported. CuClMI and CuBrMI were found to exhibit AFM bulk
properties, due to FM/AFM alternating chains along the halide-bridged polymer axis, while FM bulk
properties were confirmed for CuClPYR exhibiting a FM spin ladder. In combination with a benzamide
analogue, CuClBA, three O-donor amides, CuClMI, CuClBA and CuClPYR were analyzed and revealed
that the kinetic exchange is affected by the identity, but more importantly, the orientation of the satellite
ligands. The torsional angle of the ligand with the dimer plane is shown to significantly affect the
magnetic exchange in the dimer, and between dimers, explaining the reported FM bulk properties of
CuClPYR. This finding is exceedingly important, as it suggests that a spin device can be constructed to
flip between singlet/triplet states by manipulating the orientation of the satellite/terminal ligand.
