Synthesis, X-Ray Characterization, Spectroscopic (Ft-Ir, Uv-Vis, EPR ) and Hirshfeld Surface Analysis of Dimer Copper(Ii)-Benzoate Complex

The copper(II) complex with benzoic acid, [Cu2 (BA) 4 (BAH) 2]) (BAH: Benzoic acid) was synthesized and the original dimer complex formed by complexing copper ions with benzoic acid was investigated. The dimer complex has been characterized by spectroscopic (FT-IR, EPR, UV-Vis), structural (XRD), thermogravimetric analysis and have displayed satisfactory elemental analysis. The copper(II) compound crystallizes in the monoclinic space group P21/c, Z=4, with the unit-cell dimensions: a=10.775(5) Å, b=11.730 (5) Å, c=15.271 (4) Å, β=91.393 (4)˚. The coordination polyhedron around each copper central is described as an elongated (4+1) square pyramidal sphere. The trigonality factor (τ=(β-α)/60) value of the copper complex is 0.01 and this value expresses having slightly distorted square pyramidal environment of the Cu(II) ions coordination. Hydrogen bonds and π⋯π weak interactions form a three-dimensional supramolecular structure. The FT-IR studies of the complex were commented, focusing on the shifts in the vibrational peaks between the complex form and free benzoic acid. The powder EPR spectra of complex was investigated at liquid nitrogen temperature. As a result of EPR analysis, spin Hamiltonian parameters were obtained. In addition, zero field splitting parameters of the dimer-complex was obtained as Dobs= 0.60 cm-1 and E≈0. Thermal properties were carried out by thermogravimetric Analysis (TGA). Moreover, the intermolecular interactions have been also analyzed using Hirshfeld surface analysis.