A new copper(II) coordination polymer was synthesized
from thel-isoleucine-Schiff base and characterized by elemental
analysis,
Fourier transform infrared (FT-IR) spectroscopy, ultraviolet–visible
(UV–vis) spectroscopy, single-crystal X-ray diffraction (XRD)
analysis, electronic paramagnetic resonance, and thermogravimetric
analysis. XRD analysis confirmed the square planar coordination geometry
of metallic centers and a zipper-like polymer structure. Vibrational,
electronic, and paramagnetic spectroscopies and thermal analysis were
consistent with the crystal structure. A Hirshfeld surface (HS) and
density functional theory (DFT) analyses were employed to gain additional
insight into interactions responsible for complex packing. The quantitative
examination of two-dimensional (2D) fingerprint plots revealed, among
other van der Waals forces, the dominating participation of H···H
and H···Cl interactions in the molecular packing. The
use of computational methods provided great help in detailing the
supramolecular interactions occurring in the crystal, which were mainly
van der Waals attractions. The electronic transition analysis helped
corroborate the electronic transitions observed experimentally in
the absorption spectrum. The frequency and vibrational mode analysis
gave a deeper insight into the characterization of the CuLCLcomplex.