Synthesis, crystal and molecular structure of a new heterometallic oxo-2-methoxyethoxide, BaMo2O5(OC2H4OMe)(4)(HOC2H4OMe)

The colorless needle-shaped crystals of a new heterometallic 2-methoxyethox ide, BaMo2O5(OC2H-4OMe)(4)(HOC2H4OMe) (1), have been obtained by the satura tion of barium 2-methoxyethoxide solution in 2-methoxyethanol with the crys talline MoO2(OC24H,OMe)(2). The precipitation started when the Ba:Mo ratio achieved a 1:2 value and the precipitate formed contained BaMoO4 as an admi xture thus indicating that the formation of oxo species led partially even to formation of inorganic molybdates. Molecules of 1 involve the metal-oxyg en framework quite typical of trinuclear homo- and heterometallic alkoxide species. The rather high coordination number of the barium atom (10) and th e lengths of the observed interatomic distances permit to suggest that this atom in 1 forms predominantly ionic bonds and, therefore, complex 1 can be formulated as [Ba(HOC2H4OMe)](2+) [Mo2O5(OC2H4OMe)(4)](2-). (C) 1998 Elsev ier Science Ltd. All rights reserved.