Crystal structures of the Ba-Cu(I) alkoxides Ba4Cu6(O)(OCEt3)(12) and BaCu6(OCEt3)(8)

A single crystal of the Ba-Cu(I) oxo-alkoxide Ba4Cu6(O)(OCEt3)(12) (1) was isolated from the reaction of Ba2Cu4(OCEt3)(8) (2) with oxygen. Oxo-alkoxid e 1 crystallizes in the cubic space group 123 with the four Pa atoms distri buted tetrahedrally around the central oxide ion and six Cu(OCEt3)(2)(-) un its bridging each Pa atom to the three others. The Ba-Cu(I) alkoxides [BaCu (OCEt3)(3)](n) (3) and BaCu6(OCEt3)(8) (4) were also synthesized. Crystals were not obtained for 3, but the easily crystallized 4 has two Cu-3(OCEt3)( 4)(-) moieties coordinated to a central Pa atom, and disproportionates in s olution to many products. (C) 1998 Elsevier Science Ltd. All rights reserve d.