Crystal structure, Hirshfeld surface, physicochemical, thermal and DFT studies of (N1E, N2E)-N1,N2-bis((5-bromothiophen-2-yl)methylene)ethane-1,2-diamine N2S2 ligand and its [CuBr(N2S2)]Br complex

A new tetradentate N2S2 Schiff base ligand derived from 5-bromothiophene-2-carbaldehyde and its [CuBr(N2S2)]Br complex were synthesized in good yield. FT-IR was investigated to monitor the condensation reaction during the ligand synthesis process. The ligand, N2S2, and its complex, [CuBr(N2S2)]Br, complex have been characterized with the aid of several spectroscopic techniques such as UV-vis., MS, FT-IR, EA, EDS, NMR (for N2S2), as well as by thermal (TG/DTG) analysis. In addition, cyclic voltammetry has been employed to examine the redox behavior of [CuBr(N2S2)]Br complex in N,N'-dimethylformamide (DMF) containing 0.10 M tetra-n-butylammonium perchlorate (TBAP). The anti-conformation EE isomer of the ligand (N2S2) was confirmed by means of X-ray crystallography; ligand crystallizes in to the monoclinic P21/c space group. N2S2 ligand was subjected to DFT-theoretical calculations and results are consistent with the experimental chemical analysis.