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 [CuFeCl(Pesta)][FeCl].

Copper(I) π-coordination compounds with allyl derivatives of azoles are an interesting subject of current research, but Cu 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 Cu/Fe π-complex di-μ-chlorido-1:2κCl;2:3κCl-tetrakis[μ-5-(prop-2-en-1-ylsulfanyl)-1,3,4-thiadiazol-2-amine]-1:2κN:N;1(η),κN:2κN;2:3κN:N;2κN:3(η),κN-dicopper(I)iron(II) tetrachloridoferrate(II), [CuFeCl(CHNS)][FeCl] (1). The structure of the 5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine (Pesta, CHNS) ligand is also presented. The cationic substructure in 1 consists of one Fe and two Cu 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 [FeCl] ions. π-Coordination of the Pesta allyl group to the Cu ions prevents agglomeration of the inorganic Cu-Cl-Fe-Cl-Cu part into infinate chains. An energy framework computational analysis was performed for Pesta.