Direct Synthesis of Heterometallic Europium/Barium Complexes: H2[Eu2Ba6O2(OiPr)16(THF)4] and EuBa2(OC6H4Me-4)7(diglyme)2(DME)

Convenient syntheses of mixed-metal Eu/Ba complexes starting from the elemental metals have been explored. A mixture of europium and barium ingots reacts in boiling 2-propanol to form a product which crystallizes from THF as the heterometallic complex formulated as H ₂ [Eu ₂ Ba ₆ O ₂ (O i Pr) ₁₆ (THF) ₄ ] ( 1 ). An analogous reaction in the presence of p -cresol (HOC ₆ H ₄ Me-4) forms trimetallic EuBa ₂ (OC ₆ H ₄ Me ₄ ) ₇ (diglyme) ₂ (DME) ( 2 ), after recrystallization from THF/DME/diglyme (DME = 1,2-dimethoxyethane). Complex 1 exhibits an octametallic geometry comprised of two square pyramids with coplanar bases which share a basal edge and have apices on opposite sides. The six barium atoms occupy the basal positions and the two europium atoms are at the apices. Complex 2 exhibits a triangular arrangement of metal atoms with both terminal and bridging aryloxide ligands coordinated to the europium atom and bridging aryloxide and terminal ether ligands coordinated to the barium atoms.