The Preparation and Crystal Structure of a Unique Bismuth Complex with Ethylene Glycol: the Tris[ethane-1,2-diolato(2–)]dibismuth(III) Polymer Hydrate

Abstract

A novel efflorescent complex of bismuth(III) with ethylene glycol has been synthesized, and its structure determined by single-crystal X-ray diffraction and refined to a residual R 0·055 for 1811 observed reflections. Crystals are triclinic, space group P^-1, with two dimers forming the asymmetric unit in a cell with dimensions a 8·885(3), b 10·796(4), c 7·586(3) Å, α 93·19(3), β 106·61(3), γ 105·72(3)°. The [Bi₂(C₂H₄O₂)₃] dimer unit, which comprises two different bismuth centres, one five-, the other six-coordinate, is extended into a stable three-dimensional polymer framework via associations through all three ethane-1,2-diolato(2– ) ligands which are bidentate and, in most cases, bridging. The lattice also contains weakly associated but uncoordinated molecules of hydration which are considered responsible for the crystal instability.