Comprehensive Exploration of Optics and Magnetism in a Hydrothermally Synthesized Nickel(II) Complex

The hydrothermal
reaction of 2-MeIm (2-MeIm: 2-methylimidazole)
with nickel sulfate hexahydrate in methanol afforded a mononuclear
complex formulated as [Ni(SO4)(2-MeIm)2(H2O)3]·CH3OH (1). The title compound
was described by X-ray single-crystal diffraction, thermal assessment,
IR, and UV–vis spectroscopy. The crystal structure of 1 is composed of segregated [Ni(SO4)(2-MeIm)2(H2O)3] neutral entities and a solvent
methanol molecule. Two (2-MeIm) ligands, a sulfate group, and a water
molecule reside in the equatorial positions of the vertices in this
6-fold coordination. Two aqua ligands lay in the apical positions,
resulting in a subtly distorted octahedral framework, as was supported
by spectroscopic analysis. The complex’s self-assembly is firmly
governed by robust O–H···O/N–H···O
interactions. Further details on these bonds have been furnished via
Hirshfeld surface scrutiny and 2D fingerprint plots. As proven by
TGA/DSC analysis, raising the temperature of 1 above
60 °C instigates progressive decomposition stages, which culminates
in the production of metal oxide as the ultimate product at 700 °C.
The optical analysis suggests the dielectric nature of the material
with large direct and indirect gap energies of 5.25 and 4.96 eV, respectively.
The results of magnetic studies suggest that 1 undergoes
a transition to a magnetically ordered state below 6 K.