Synthesis, Characterization, and Computational Studies of the Zinc Bromide Complex with 2-Amino-1,3,4-thiadiazole

A new mononuclear heteroleptic complex bis(2-amino-1,3,4-thiadiazole-N)-dibromo zinc(II), [ZnBr₂L₂] (1), which was obtained from 2-amino-1,3,4-thiadiazole (L), is reported. Complex 1 was studied by elemental analysis, FT-IR spectroscopy and single crystal X-ray diffraction. Crystal packing of complex 1 was additionally studied using the Hirshfeld surface analysis. The DFT/B3LYP/6-31++G(d,p) based computations were additionally applied to reveal electronic features of the obtained complex 1. It was established that complex 1 contains two parent ligands L, which are monocoordinated through the thiadiazole 3-nitrogen atom and the coordination sphere of the metal cation is filled by two bromide anions. The molecular structure of complex 1 is stabilized by one N–H \( \cdots \) N and one N–H \( \cdots \) Br hydrogen bonds. Molecules of 1 are interlinked through a myriad of N–H \( \cdots \) N and N–H \( \cdots \) Br hydrogen bonds, and S \( \cdots \) Br and π \( \cdots \) π interactions, yielding a 3D supramolecular structure. Theoretical calculations revealed a strong electrophilic nature of the optimized structure of 1 with the most electro-rich and electron-deficient sites observed on the bromide anions and NH₂ hydrogen atoms, which are not involved in the formation of intramolecular hydrogen bonds, respectively.