Synthesis and properties of erbium isopropoxides: Structural characterization of Er5O(OPri)(13)

We have investigated the synthesis of erbium isopropoxides by dissolution o f Er metal in 2-propanol-containing solvents or by metathesis of ErCl3 and KOPri in solution, with or without addition of water. Two different erbium isopropoxides could be isolated in pure form: one with a structure that has not been solved (I), which,ve believe to be a solvated non-ore isopropoxid e, and one oxo isopropoxide, Er5O(OPri)(13). The latter structure was deter mined by single-crystal X-ray diffraction; it has orthorhombic space group symmetry Pbca, a = 20.917(6) Angstrom, b = 21.575(6) Angstrom, c = 25.638(6 ) Angstrom, with Z = 8. The final R value was 0.0748 (R-w, = 0.1158). The o xo isopropoxide molecules contain the well-known M5O fragment, which has th e configuration of a square pyramid with the oxo-oxygen atom slightly above the basal plane. The compounds have been characterized by FT-IR and UV-vis spectroscopy, differential scanning calorimetry, and their solubilities an d chemical reactivities. FTIR studies revealed that both alkoxides largely retained the molecular structure when dissolved in toluene-2-propanol (2 :1 ) or hexane, The stability of Er5O(OPri)(13) in the absence of water is rat her high, whereas I is more labile. (C) 1998 Academic Press.