[ER2AL2((OPR)-PR-I)(12)((HOPR)-PR-I)(2)], A NOVEL HETEROBIMETALLIC ALKOXIDE

A new heterobimetallic tetranuclear alkoxide of the Er-Al system, [Al2 Er2(C3H7O)(12)(C3H8O)(2)], has been synthesized and characterized by s ingle-crystal X-ray diffraction and LR spectroscopy. akis(isopropoxo)b is(2-propanol)dialuminiumdierbium has the linear composition [((OPr)-P r-i)(2)Al]-(mu(2)- -Pr-i)]-(mu(2)-(OPr)-Pr-i)(2)-[Al((OPr)-Pr-i)(2)]. The inner pair of Er atoms are each sixfold coordinated and the outer Al atoms are each fourfold coordinated by O atoms. Two intramolecular hydrogen bonds exist between the 2-propanol group at the Er atom and t he monodentate isopropoxo ligand at the adjacent Al atom. The adopted chain geometry of four alkoxo-bridged metal atoms is a rather unusual structural feature for heterobimetallic (M2M'(2)) alkoxides.