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]

Abstract

Copper(I) π-coordination compounds with allyl derivatives of azoles are an interesting subject of current research, but Cu^I 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^I/Fe^II 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 Fe^II and two Cu^I 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 Cu^I ions prevents agglomeration of the inorganic Cu-Cl-Fe-Cl-Cu part into infinate chains. An energy framework computational analysis was performed for Pesta.

Keywords: 1,3,4-thiadiazole; allyl derivative; computational chemistry; copper(I); crystal structure; energy framework; heterometallic; η2-interaction.