Synthesis, structure and computational study of 5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine (Pesta) and its heterometallic π,σ‐complex [Cu2FeCl2(Pesta)4][FeCl4]

Copper(I) π‐coordination compounds with allyl derivatives of azoles are an interesting subject of current research, but CuI π‐complexes with other transition‐metal ions incorporated in the structure have been virtually uninvestigated. The present work is directed toward the synthesis and structural characterization of the novel heterometallic CuI/FeII π‐complex di‐μ2‐chlorido‐1:2κ2Cl;2:3κ2Cl‐tetrakis[μ2‐5‐(prop‐2‐en‐1‐ylsulfanyl)‐1,3,4‐thiadiazol‐2‐amine]‐1:2κ2N4:N3;1(η2),κN4:2κN3;2:3κ2N3:N4;2κN3:3(η2),κN4‐dicopper(I)iron(II) tetrachloridoferrate(II), [Cu2FeCl2(C5H7N3S2)4][FeCl4] (1). The structure of the 5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine (Pesta, C5H7N3S2) ligand is also presented. The cationic substructure in 1 consists of one FeII and two CuI ions bridged by two chloride ions along with two σ,σ‐ and two π,σ‐coordinated ligands, whereas the anionic part is built of isolated tetrahedral [FeCl4]2− ions. π‐Coordination of the Pesta allyl group to the CuI ions prevents agglomeration of the inorganic Cu–Cl–Fe–Cl–Cu part into infinate chains. An energy framework computational analysis was performed for Pesta. [ABSTRACT FROM AUTHOR]