Phenyl thiosemicarbazide cyclization leads to the versatile 1,3,4-thiadiazole scaffold: Structural analysis of its copper(I) complex

• Novel 2-phenylamino-1,3,4-thiadiazole synthesized via unexpected cyclization. • The coordination of the thiadiazole scaffold towards Cu(I) is investigated. • The 1D polymeric structure of the complex is analysed by X-ray diffraction. • The complex exhibits solid-state white emission. In an attempt to extend the synthesis of N,N-dialkyl formamidines to thiosemicarbazides, we unexpectedly obtained 2-phenylamino-1,3,4-thiadiazole as the cyclization product. Since the coordination chemistry of this versatile scaffold is poorly investigated, we have examined its interaction with CuI, resulting in the isolation of a novel 1D coordination polymer. In this polymer, each copper(I) ion is coordinated to two nitrogen atoms from two different 1,3,4-thiadiazole ligands, along with two iodide ions, forming a distorted tetrahedral geometry. Notably, the copper(I) complex exhibits solid-state white emission.