Thioalcohols as bridging ligands in polynuclear PrIII/CuII and BaII/CuII complexes. Syntheses, structures and magnetic properties of Pr2Cu4(tde)3(Htde)2(hfacac)4(µ6-O), Ba2Cu2(Htde)2(hfacac)4 and Cu4(tde)2(hfacac)4, (H2tde = HOCH2CH2SCH2CH2OH)‡

Abstract

The syntheses of heterometallic compounds involving praseodymium, barium and copper ions by using 2,2′-thiodiethanol (H₂tde) as the bridging ligand have been investigated. Three new polynuclear compounds, Pr₂Cu₄(tde)₃(Htde)₂(hfacac)₄(µ₆-O) 1, Ba₂Cu₂(Htde)₂(hfacac)₄ 2 and Cu₄(tde)₂(hfacac)₄ 3 have been obtained and characterized structurally. The metal atoms in 1 have an octahedral arrangement with the two Pr^III occupying two opposite vertices. In the center of the octahedron is a µ₆-oxygen atom. The metal atoms in 2 have a rhombic arrangement with a long Cu· · ·Cu separation distance (6.082 Å). The metal ions in 3 also have a rhombic arrangement with the copper atoms in close proximity to each other. The sulfur atoms of the Htde^– or tde^2– ligand are bound exclusively to copper centers in all three compounds. The Htde^– and tde^2– ligands display versatile bonding modes in the three compounds. Antiferromagnetic exchanges dominate in these compounds.