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 PrIII 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 tde2– ligand are bound exclusively to copper centers in all three compounds. The Htde– and tde2– ligands display versatile bonding modes in the three compounds. Antiferromagnetic exchanges dominate in these compounds.